Run PhotoPicker in a different process

Previously, PhotoPicker was running within MediaProvider process. This
means, if PhotoPicker crashes, MediaProvider will also crash, which
affects apps that are interacting with MediaProvider. Running
PhotoPicker in different process will avoid these issues.

Bug: 187831896
Test: presubmit

Change-Id: I22bc3402920671361e795bbcbbf685a54ce18eb9
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 9352cfe..c719034 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -153,6 +153,7 @@
 
         <activity
                 android:name="com.android.providers.media.photopicker.PhotoPickerActivity"
+                android:process=":PhotoPicker"
                 android:theme="@style/PickerDefaultTheme"
                 android:exported="true"
                 android:excludeFromRecents="true"