Inverted the new data stack flag

Invert the flag so even if this flag does not exist in the
resource, the new data stack is still enabled by default.

Also deleted unit tests that are only applicable to old
data stacks.

Fix: 228813515
Test: Manual && atest FrameworksTelephonyTests
Change-Id: I3513de313260bd2273add89ac47fdab3406be891