Camera: Make originalDataSpace be const upon stream creation

The previous logic was wrong(!) where DATASPACE_UNKNOWN shouldn't be
used as an initializtion condition.

Test: CTS and vendor testing
Bug: 139820060
Change-Id: I6b59d40ff796d48fe1804b45c189004f1ecc8c18
diff --git a/services/camera/libcameraservice/device3/Camera3Stream.h b/services/camera/libcameraservice/device3/Camera3Stream.h
index 67afd0f..805df82 100644
--- a/services/camera/libcameraservice/device3/Camera3Stream.h
+++ b/services/camera/libcameraservice/device3/Camera3Stream.h
@@ -588,7 +588,7 @@
 
     //Keep track of original dataSpace in case it gets overridden
     bool mDataSpaceOverridden;
-    android_dataspace mOriginalDataSpace;
+    const android_dataspace mOriginalDataSpace;
 
     String8 mPhysicalCameraId;
     nsecs_t mLastTimestamp;