Make MANAGE_ACTIVITY_STACKS a signature|system permission.
Make MANAGE_ACTIVITY_STACKS a signature|system permission.

To allow ActivityView support within privileged apps.

Change-Id: Ic0246939bf71c52ca9415149415a976537c8270b

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base