HWUI: mSerialContext needs to outlive other serializing members

mSerialContext is used as the serialization context, and need to
outlive mOpenMultiPicStream and mMultiPic and those are referencing
it in SkSharingSerialContext SkSharingSerialContext::serializeImage

Test: https://buganizer.corp.google.com/issues/182710292#comment16
Bug: 183049238
Change-Id: I25842e492d5efd7a7532964bddca61559d50ebe1

libs/hwui/pipeline/skia/SkiaPipeline.h

@@ -137,9 +137,10 @@ private:
     int mCaptureSequence = 0;
 
     // Multi frame serialization stream and writer used when serializing more than one frame.
+    std::unique_ptr<SkSharingSerialContext> mSerialContext;  // Must be declared before any other
+                                                             // serializing member
     std::unique_ptr<SkFILEWStream> mOpenMultiPicStream;
     sk_sp<SkDocument> mMultiPic;
-    std::unique_ptr<SkSharingSerialContext> mSerialContext;
 
     /**
      * mRecorder holds the current picture recorder when serializing in either SingleFrameSKP or