camera_metadata: Add supportedHardwareLevel field

Bug: 9111852
Change-Id: I6a01cb2678c8cd824eb2eb84d69d47a524c20750
Merge tag 'android-4.3_r3.1' of https://android.googlesource.com/platform/system/media into cm-10.2

Android 4.3 Release 3.1