Separate 2 tests to verify canBeSatisfiedBy()

In Android R, NetworkSpecifier#satisfiedBy() has changed to
NetworkSpecifier#canBeSatisfiedBy(), but its subclass -
MatchAllNetworkSpecifier hasn't.
In Android S, both of MatchAllNetworkSpecifier and
NetworkSpecifier has changed satisfiedBy() to canBeSatisfiedBy().
So if running the latest CTS on R device, it will verify
NetworkSpecifier#canBeSatisfiedBy() instead of
MatchAllNetworkSpecifier#satisfiedBy() and get the unexpected
result.
The fix is to separate 2 tests to verify canBeSatisfiedBy(), one
is for Android R or older version and the other is for Android
S+.

Bug: 172401624
Test: Run MatchAllNetworkSpecifierTest on Android R and S.
Change-Id: I1391bae9a0fc0298beb8fe80b5f388b492244566