Camera: Destroy jpeg handle in 'encodeGrayscaleJpeg'

Make sure 'jpeg_destroy_compress()' is always called
before leaving 'encodeGrayscaleJpeg()'.
Additionally fix misspelling of 'intrinsic'.

Bug: 135622974
Test: atest
cts/tests/camera/src/android/hardware/camera2/cts/StillCaptureTest.java#testDynamicDepth
--generate-baseline=12
Change-Id: I55c1f86881ba05aac6aac6981df5fcb276c9d4da