Fix intent filter for ManageExternalSourcesActivity

Also fix fragment nesting so the activity is styled correctly

Bug: 38496265
Test: adb shell am start -a android.settings.MANAGE_UNKNOWN_APP_SOURCES package:com.example.app
Change-Id: Iefe4d47eea9ed92e74631c0ed02e639e66a913f1
(cherry picked from commit 252036fc847c5deaeb8906fc93b8fcd61fb4ff66)
(cherry picked from commit d00bb30c3e82064f1f1884d72a37479f9ffaf180)
2 files changed
tree: a03429cb4d9a898a1c44a4c9f64c9fd1a7daff6c
  1. PREUPLOAD.cfg
  2. QuickSettings/
  3. Settings/