EGL: Plumb HDR metadata

HDR metadata comes in bit by bit via eglSurfaceAttribute.
Don't want to call native_window_set_buffers_smpte2086_metadata
for every piece, instead wait until eglSwapBuffers and call
native_window_set_buffers_smpte2086_metadata then.
Does require changing the state of the surface, so some const
goes away.

Bug: 63710530
Test: adb -d shell am start -n \
      com.drawelements.deqp/android.app.NativeActivity \
      -e cmdLine '"deqp --deqp-case=dEQP-EGL.functional.hdr_metadata.* \
      --deqp-log-filename=/sdcard/dEQP-Log.qpa"'
Test: adb shell /data/nativetest/test-opengl-gl2_basic/test-opengl-gl2_basic
Test: adb shell /data/nativetest/test-opengl-gl_basic/test-opengl-gl_basic
Change-Id: I2e428ec18737f6caa8c0e1893705b7796fd77272
6 files changed