Themes: uninstallThemeForAllApps shouldn't check if map is empty if it's null

Potential NPE introduced in ec2200878706735cdd2caf4d934d988296998e85

Change-Id: I6d1ec165957c2be63086a18af2236e46978e9c8a
android 4.4.3_r1.1 update

Change-Id: I2c0d233e93e09ced3ba1d9d4de6a6f3546f58d08
Merge remote-tracking branch 'upstream/android-4.4' into android-4.4