optimize the default path string for Launcher3

Bug: 372884380
Bug: 426259519
Test: v2/android-crystalball-eng/health/microbench/bootup/idle/system-processes-memory-direct-aosp
Flag: com.android.launcher3.enable_launcher_icon_shapes
Change-Id: Ibf73b96bfb07c17bdf57b78f16d69699e7889e05