Add relayout debug support in Launcher

This adds support for measure/layout tracing in Launcher (in sysui it has already been enabled in T)

When enabled, traces for each class measure and layout are output in
a perfetto trace. This adds some overhead, so it's disabled by default, but extremely useful for testing and debugging long doFrames.

To enable request layout tracing for a specific class X, the following helper can be used:

trace_class_layouts() {
        adb shell setprop persist.debug.trace_request_layout  1
        adb shell setprop persist.debug.trace_request_layout_class $1

        adb shell am force-stop com.google.android.apps.nexuslauncher
        adb shell am force-stop com.android.systemui
}

Then, use `trace_class_layouts X` and record a perfetto trace
e.g. `trace_class_layout BubbleTextView`

To just see class breakdown of measure/layout setting `persist.debug.trace_request_layout` is sufficient.

Test: record a trace after enabling options
Bug: 266090955
Change-Id: I4f621ebaaec6a07cd7c0693aa8876158cc60e208