fix edge-to-edge in MediaPreviewActivity

Author: adbenitez

src/main/res/layout/media_preview_activity.xml

@@ -3,6 +3,7 @@
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
+                android:fitsSystemWindows="true"
                 android:background="@color/gray95">
 
     <org.thoughtcrime.securesms.components.viewpager.HackyViewPager