The next change will update the locking around eglSwapBuffers. Move
all the locking into libEGL.cpp to avoid duplicating getDisplayLock().

Bug: b/135742693
Test: built locally
Test: presubmit
Test: cts -m CtsMediaTestCases -t android.media.cts.HeifWriterTest#testInputSurface_Grid_Handler
Change-Id: I1ca863b4902d1dc4e456700ac96aecc3e61424ba
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/37768
Presubmit-Ready: Jason Macnak <natsu@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Jason Macnak <natsu@google.com>