Reference ctable when adopting pointer in Bitmap

Change-Id: I56aea10928f0ec73756ed055488a3e3516a9096e
Test: manual.
bug:32621254, 32561595
(cherry picked from commit 003f14256271a6955baacba93e54f09d366f1c3b)
diff --git a/libs/hwui/hwui/Bitmap.cpp b/libs/hwui/hwui/Bitmap.cpp
index be0b22e..da63c18 100644
--- a/libs/hwui/hwui/Bitmap.cpp
+++ b/libs/hwui/hwui/Bitmap.cpp
@@ -307,7 +307,7 @@
     }
     mRowBytes = rowBytes;
     if (mColorTable.get() != ctable) {
-        mColorTable.reset(ctable);
+        mColorTable.reset(SkSafeRef(ctable));
     }
 
     // Need to validate the alpha type to filter against the color type