Surface: don't hold mMutex when queuing buffers

This is the behavior of the underlying IGBP, but can cause deadlocks in
certain situations dependend on by some clients.

BYPASS_IGBP_IGBC_API_REASON=warren buffers

Bug: 340933794
Flag: com.android.graphics.libgui.flags.wb_platform_api_improvements
Test: new test in `atest libgui_test`
Change-Id: I5a02e6e12980d211e70ae4db8cbd2344e323d613