Expose color filter mutate methods

Bug: 36025103
Test: cts-tradefed run singleCommand cts-dev --module CtsGraphicsTestCases

Now, similar to Shaders, we defer native creation until Paint is being
used, and ensure that we have an up to date filter when drawing.

Also implements ColorMatrix#equals to behave like Matrix#equals.

Change-Id: I5f74addd97f5662800802e6f660fead58d518725

tests/HwAccelerationTest/src/com/android/test/hwui/ColorFiltersMutateActivity.java

@@ -138,7 +138,7 @@ public class ColorFiltersMutateActivity extends Activity {
             mSaturation = saturation;
             final ColorMatrixColorFilter filter =
                     (ColorMatrixColorFilter) mColorMatrixPaint.getColorFilter();
-            final ColorMatrix m = filter.getColorMatrix();
+            final ColorMatrix m = new ColorMatrix();
             m.setSaturation(saturation);
             filter.setColorMatrix(m);
             invalidate();