A better HW Bitmap uploader

Move all HW bitmap upload operations off of RenderThread.
Ensure EGL context outlives all upload requests

Bug: 79250950
Test: builds, boots, systrace is good, CTS bitmap tests pass

Change-Id: I5ace6c516d33b1afdf1a407cd8b183f6b60c22c1
diff --git a/libs/hwui/renderthread/EglManager.h b/libs/hwui/renderthread/EglManager.h
index ca6d1b8..8e8bb8b 100644
--- a/libs/hwui/renderthread/EglManager.h
+++ b/libs/hwui/renderthread/EglManager.h
@@ -64,6 +64,8 @@
 
     void fence();
 
+    EGLDisplay eglDisplay() const { return mEglDisplay; }
+
 private:
 
     void initExtensions();