Don't modify invariant device profile

We flag guard the code that modifies IDP as that's not needed with one
grid, and we don't want to modify idp outside of it

Bug: 332974074
Flag: com.android.launcher3.one_grid_specs
Test: verified manually with b&r
Change-Id: Ica2ffa79638fa693cde421adb13feebb0d09cbc4