Why RecyclerView occupies entire layout space even though its layout_height attribute is set to wrap_content?

Question

I need to add a RecyclerView such that when there is a child element it should be visible or else it shouldn't be visible. So I have set the android:layout_height attribute to wrap_content thinking that it does the above work.

But when I does that the content above RecyclerView in Android is visible and the rest of the layout space is occupying by the RecyclerView.

So now can we do anything to make RecyclerViews height to be dynamic?

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:orientation="vertical"
          android:padding="32dp"
android:weightSum="1">

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:includeFontPadding="false"
    android:text="@string/feedback_header"
    android:textAppearance="?android:attr/textAppearanceMedium"/>

<EditText
    android:id="@+id/feedback"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="16dp"
    android:background="@color/white"
    android:gravity="start|top"
    android:hint="@string/feedback_description"
    android:maxLines="5"
    android:minLines="5"
    android:padding="8dp"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@color/darkGray"/>

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:text="@string/feedback_no_files"
    android:textAppearance="?android:attr/textAppearanceSmall"/>

<android.support.v7.widget.RecyclerView
    android:id="@+id/attach_file_list"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:text="@string/feedback_disclosure"
    android:textAppearance="?android:attr/textAppearanceSmall"/>

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/report"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/darkGray"
        android:padding="8dp"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:textColor="@color/white"/>

</ScrollView>

</LinearLayout>