Remove Ikev2VpnProfile shims usage

Remove usage of Ikev2VpnProfileShim and Ikev2VpnProfileBuilderShim.

Both were used to allow the test to build in branches that do not have T
APIs, but all downstream branches now do.

The shims would throw checked exceptions when unsupported methods were
used, not providing fallback behavior, so they can just be replaced by
direct calls in any case.

Bug: 232251248
Test: atest Ikev2VpnTest
Change-Id: I1d5418206fab9f35403eb3baf81363b1286b0b3b
1 file changed