Expose bitDepth to MediaMetadataRetriever

Bug: b/217378477
Test:
Change-Id: I16dabdf9aaabf341a9cebb1624e464155196a5a8
diff --git a/media/libheif/include/HeifDecoderAPI.h b/media/libheif/include/HeifDecoderAPI.h
index fa51aef..56f4765 100644
--- a/media/libheif/include/HeifDecoderAPI.h
+++ b/media/libheif/include/HeifDecoderAPI.h
@@ -46,7 +46,8 @@
     uint32_t mHeight;
     int32_t  mRotationAngle;           // Rotation angle, clockwise, should be multiple of 90
     uint32_t mBytesPerPixel;           // Number of bytes for one pixel
-    int64_t mDurationUs;               // Duration of the frame in us
+    int64_t  mDurationUs;              // Duration of the frame in us
+    uint32_t mBitDepth;                // Number of bits of R/G/B channel
     std::vector<uint8_t> mIccData;     // ICC data array
 };
 
@@ -162,6 +163,11 @@
      */
     virtual size_t skipScanlines(size_t count) = 0;
 
+    /*
+     * Returns color depth of R/G/B channel.
+     */
+    virtual uint32_t getColorDepth() = 0;
+
 private:
     HeifDecoder(const HeifFrameInfo&) = delete;
     HeifDecoder& operator=(const HeifFrameInfo&) = delete;