opengl: Fix pixelDataSize() ambiguity.

opengl: Fix pixelDataSize() ambiguity.

The GLESv1 encoder library was calling the pixelDataSize() function
definition from the GLESv2 encoder library, resulting in bugs, like
the inability to see the boot animation when -gpu on is used.

This fixes the issue by using namespaces to differentiate the
two implementations. Note that the auto-generated files have been
updated by re-running update-emugl-sources.sh as specified by
opengl/README after applying the following patches:

  https://android-review.googlesource.com/#/c/116642/
  https://android-review.googlesource.com/#/c/116643/
  https://android-review.googlesource.com/#/c/116644/

Change-Id: Idbd84fb6ca5934cbb9af009b09f9a38cc4a1340a