Android camera: Replace custom matrix operations with android.opengl.Matrix

Bug: webrtc:9412, webrtc:9487
Change-Id: I68e5a03026b1ab8236a05ece79690d4a8755c093
Reviewed-on: https://webrtc-review.googlesource.com/86947
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23851}
diff --git a/sdk/android/api/org/webrtc/VideoFrame.java b/sdk/android/api/org/webrtc/VideoFrame.java
index 6d19260..4afe782 100644
--- a/sdk/android/api/org/webrtc/VideoFrame.java
+++ b/sdk/android/api/org/webrtc/VideoFrame.java
@@ -118,7 +118,7 @@
      * homogeneous coordinates of the form (s, t, 1) with s and t in the inclusive range [0, 1] to
      * the coordinate that should be used to sample that location from the buffer.
      */
-    public Matrix getTransformMatrix();
+    Matrix getTransformMatrix();
   }
 
   private final Buffer buffer;