swapchain: Fix auto-merger defect: Fix SHARED presentation modes

Part of aosp/1921342 did not end up in goog/master.  This fixes that.

Test: dEQP.EGL/functional_mutable_render_buffer_basic
Bug: 209035115
Bug: 200378297
Change-Id: Id5bf9c5af8e60184f575517e3209482953535a20
1 file changed