Camera service: Updates in preparation for HIDL

- For all camera2 paths, and anything shared between the legacy API and
  camera2, switch to using strings for camera IDs
- Update ICameraService.addListener to return current set of known
  devices and their status, to allow for immediate return of camera
  devices when first connecting to camera service
- Remove unused code path for getCameraCharacteristics with HALv1
- Add namespace qualifiers to Binder objects that are also used by
  hardware binder.
- Switch to using new HIDL DeviceStatus and TorchStatus enumerations
  for better type safety in the service; map more clearly between
  the HAL, service-internal, and Binder enums.

Test: cts-tradefed run cts -m Camera --skip-connectivity-check -d -o --abi armeabi-v7a --disable-reboot
Bug: 32991422
Change-Id: I765951d9a21000a8432bed9aa0e3604709daa4b1
diff --git a/include/camera/android/hardware/ICameraClient.h b/include/camera/android/hardware/ICameraClient.h
index 3f835a9..f6ee311 100644
--- a/include/camera/android/hardware/ICameraClient.h
+++ b/include/camera/android/hardware/ICameraClient.h
@@ -27,7 +27,7 @@
 namespace android {
 namespace hardware {
 
-class ICameraClient: public IInterface
+class ICameraClient: public android::IInterface
 {
 public:
     DECLARE_META_INTERFACE(CameraClient);
@@ -45,7 +45,7 @@
 
 // ----------------------------------------------------------------------------
 
-class BnCameraClient: public BnInterface<ICameraClient>
+class BnCameraClient: public android::BnInterface<ICameraClient>
 {
 public:
     virtual status_t    onTransact( uint32_t code,