SnapdragonCamera: Using reflection to remove compilation error

Issue:
Currently the camera app is being used across multiple PLs,
which are on different android versions (Android M, N).
There are different variables being used for h256 across
different android framework - M and N. Hence using one
variable name is causing compilation error in other android
version

Fix:
Using java reflection to access variables to avoid any
compilation dependency on different android versions

CRs-Fixed: 1015477
Change-Id: I68519223dbe9825e8b1a7f5d1a8e509713a743c6
2 files changed