Camera: Use separate lock for mStreamingRequestId

There are cases where evictClientIdByRemote holds
mBinderSerializationLock and waits for mRequestLock, and at the same
time checkAndStopRepeatingRequest holds mRequestLock and waits for
mBinderSerializationLock, causing deadlock.

Solution is to use separate lock to protect mStreamingRequestId.

Bug: 28295136
Change-Id: I40f8e1ded29abde86bc12b20dd119f9f3371ebb2
diff --git a/services/camera/libcameraservice/api2/CameraDeviceClient.h b/services/camera/libcameraservice/api2/CameraDeviceClient.h
index 3660a18..d792b7d 100644
--- a/services/camera/libcameraservice/api2/CameraDeviceClient.h
+++ b/services/camera/libcameraservice/api2/CameraDeviceClient.h
@@ -208,6 +208,7 @@
 
     // Streaming request ID
     int32_t mStreamingRequestId;
+    Mutex mStreamingRequestIdLock;
     static const int32_t REQUEST_ID_NONE = -1;
 
     int32_t mRequestIdCounter;