Update NDK methods for HARDWARE Bitmaps

Bug: 135133301
Test: I2c1e58c41e49c72fb4bdbc64989da103885d34bf

_getInfo now sets a bit in AndroidBitmapInfo.flags to indicate whether
the Bitmap has Config.HARDWARE.

For a HARDWARE Bitmap, its AHardwareBuffer can now be retrieved with
AndroidBitmap_getHardwareBuffer. Call AHardwareBuffer_acquire on the
buffer so it will not be deleted while the client is using it.

Change-Id: I9240c1928c1478053ecf7c252443a33dbd6fd6db