Add new config config_supportsSystemDecorsOnSecondaryDisplays.

Use this config to decide should we run
MultiDisplaySystemDecorationTests test. This value can be overlay
if OEM cannot support related features to skip those tests.

Bug: 126921702
Test: atest MultiDisplaySystemDecorationTests ActivityManagerMultiDisplayTests
Change-Id: I95b699b0958c25c2107ea66d202b3b28213fa820