Update language to comply with inclusive guidance

Update android_app_set make files to use INSTALL rather than MASTER for
android_app_sets, this better matches the wording used for apex_set.

See https://source.android.com/setup/contribute/respectful-code for
reference

Bug: 161896447
Test: m nothing
Change-Id: I7f37a72914f4b18a839942cc3db98b1c57db921e