drm_hwcomposer: Clear staged_mode_config_id_ after SetConfig
It's possible that a config change could be queued to happen at the next composition, but that composition doesn't happen. In such a case, staged_mode_config_id_ remains set.
If a blocking SetConfig call happens, clear staged_mode_config_id_ so that ensuing calls to getActiveConfig will not erroneously return the stale staged_mode_config_id_.
Change-Id: I087eea140f3c02dd0c775ab742ad2d511a0e66cc Signed-off-by: Drew Davenport ddavenport@google.com