Camera2: Re-enable disabled LEGACY tests.

Re-enables disabled tests:
- CaptureRequestTest#testAeModeAndLock
- CaptureRequestTest#testFaceDetection
- PerformanceTest#testSingleCapture
- StillCaptureTest#testJpegExif
- StillCaptureTests#testStillPreviewCombination
- StillCaptureTests#testAeRegions
- StillCaptureTests#testAfRegions
- SurfaceViewPreviewTest#testCameraPreview
- ImageReaderTest#testJpeg
- ImageReaderTest#testRepeatingJpeg
- ImageReaderTest#testYuvAndJpeg
- RecordingTest#testVideoSnapshot
- RecordingTest#testBurstVideoSnapshot
- RobustnessTest#testMandatoryOutputCombinations

Bug: 17730340
Change-Id: Id892d3bc3e5c429013c39129f40c7da370d81e62