Log at debug level when things are OK

StorageManagerService: android.os.ServiceSpecificException is expected if the user has not unlocked the device.

Bug: 151077642
Bug: 174442693
Change-Id: I07b06cd6f7cff4529cba46aa4e3dcf7b0ee8dfa5
Test: No
Merged-In: I027250bcae132d9be9c16690478adb41467bfec4