Temporary flag for Launcher to debug their usage of sandboxed display APIs

The flag does not impact any other application calling the sandboxed
display APIs. The flag will be removed after Launcher finishes
identifying the breakages attributed to the display API changes.

For Launcher to receive the un-sandboxed values:
adb shell cmd display constrain-display-apis false

Test: manual
Bug: 193421404
Change-Id: I5d8612fd7dcb49769ae005130c9786b2d8416bfc