Change ellipsize mode of window caption

This improves performance as fading edges are GPU-heavy.
Metrics: https://android-build.corp.google.com/abtd/run/L22400030008498456/

Bug: 382366712
Test: manual - verified on a few font sizes and few different app names
Flag: com.android.window.flags.enable_desktop_windowing_mode
Change-Id: I864f4d21e9cb560e05ec88b936fe91809a810192