Move Gallery2 to androidx.

Bug: 76692459
Test: make -j Gallery2 and run on emulator
Change-Id: Ife6a5649c21464f404db3198bd6a4ba8aa901ee8
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index c79d976..18b83ca 100755
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -329,7 +329,7 @@
                 android:syncable="false"
                 android:exported="false"/>
         <provider
-            android:name="android.support.v4.content.FileProvider"
+            android:name="androidx.core.content.FileProvider"
             android:authorities="com.android.gallery3d.fileprovider"
             android:exported="false"
             android:grantUriPermissions="true">