fix android dm compile

TBR=djsollen@google.com
NOTRY=true
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4489
Change-Id: I77446143ab8f310bd9f63c99b49cde59b1c9604a
Reviewed-on: https://skia-review.googlesource.com/4489
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>

dm/DMSrcSinkAndroid.cpp

@@ -53,7 +53,7 @@ Error ViaAndroidSDK::draw(const Src& src,
 
             // Pass through another proxy to get paint transforms
             SkAndroidSDKCanvas fc;
-            fc.reset(scProxy);
+            fc.reset(scProxy.get());
 
             fSrc.draw(&fc);