Fix FindBugs issues

IntProperty: Infinite recursive loop
SQLiteSession: Null pointer dereference
UsbStoreActivity: Null pointer derefence
LocationManagerService: No relationship between generic parameter and method argument
ActivityManagerService: Call to equals() comparing different types
ChooseAccountTypeActivity: Possible null pointer dereference
RuimRecords: Possible null pointer derefence

Change-Id: I9d631c50c30eb98e32cca5a5085513b6904db676
Keyguard: enable widgets on lowram devices

Change-Id: Icf5d6982b4729153ddeb26e9fbb648392bb96e66