camera: Disable extra HDR frame on QCOM_HARDWARE

Qualcomm camera HALs default to adding an extra zero-exposure frame
to HDR snapshots; this is breaking third-party apps, and we don't
use it in system-bundled apps, so disable it unless explicitly
requested by the client

Change-Id: Iecb868c5c344d972de7f36dc1bd9cc9fdbabaf4e
Merge pull request #4 from omnirom/android-4.4

camera: Disable extra HDR frame on QCOM_HARDWARE