Temporarily disabling tests for disabled feature

Some tests relying on the flag were left enabled by mistake.

Test: atest FrameworksServicesTests:com.android.server.net

Bug: 304347838
Bug: 325685265
Change-Id: I17a9fcaaa44f2c8b43c19e3445a329c8613ee3dd
Merged-In: I17a9fcaaa44f2c8b43c19e3445a329c8613ee3dd