Align shape to center of textview on Relative layout

You cannot accomplish what you're trying to do using RelativeLayout. It only allows you to specify one rule for vertical alignment (e.g. layout_alignTop or layout_alignBottom) and there's no "alignCenterVertically" or similar.

You could instead try using ConstraintLayout, which does allow you to specify multiple constraints for vertical alignment. You have to convert all of your android:layout_below attributes to app:layout_constraintTop_toBottomOf, and you have to convert all of your android:layout_toRightOf attrs to app:layout_constraintLeft_toRightOf, but the conversion is overall pretty simple. Once you've done that, you can add these two constraints to your circle ImageView:

app:layout_constraintTop_toTopOf="@+id/rvDescripcion"
app:layout_constraintBottom_toBottomOf="@+id/rvDescripcion"

Here's the whole thing:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/swipeLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="8dp">

        <ImageView
            android:id="@+id/rvSincronizado"
            android:layout_width="10dp"
            android:layout_height="10dp"
            android:layout_marginLeft="5dp"
            android:gravity="center_vertical"
            android:background="@drawable/circle"
            app:layout_constraintTop_toTopOf="@+id/rvDescripcion"
            app:layout_constraintBottom_toBottomOf="@+id/rvDescripcion"/>

        <TextView
            android:id="@+id/rvDescripcion"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:textColor="#000000"
            android:text="PRENSA"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintLeft_toRightOf="@id/rvSincronizado"/>

        <TextView
            android:id="@+id/rvetMarca"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:text="@string/rvetMarca"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvDescripcion"/>

        <TextView
            android:id="@+id/rvMarca"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvDescripcion"
            app:layout_constraintLeft_toRightOf="@+id/rvetMarca"/>

        <TextView
            android:id="@+id/rvetModelo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:text="@string/rvetModelo"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvDescripcion"
            app:layout_constraintLeft_toRightOf="@id/rvMarca"/>

        <TextView
            android:id="@+id/rvModelo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvDescripcion"
            app:layout_constraintLeft_toRightOf="@+id/rvetModelo"/>

        <TextView
            android:id="@+id/rvetSerie"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:text="@string/rvetSerie"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvetMarca"/>

        <TextView
            android:id="@+id/rvSerie"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:layout_marginLeft="5dp"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:layout_constraintTop_toBottomOf="@id/rvetModelo"
            app:layout_constraintLeft_toRightOf="@+id/rvetSerie"/>

    </android.support.constraint.ConstraintLayout>

</LinearLayout>