Move VpnManagerServiceTest and VpnTest to frameworks

These unit tests are closely tied to the source code in
frameworks/base and were incorrectly placed in the connectivity
module. Also update the libraries visibility that are used by
the tests.

Test: atest FrameworksNetTests
Change-Id: I196c33a8bd5b5cdb9d42aea381e900681ff6d25e
diff --git a/framework/Android.bp b/framework/Android.bp
index 8fa336a..5a33ca7 100644
--- a/framework/Android.bp
+++ b/framework/Android.bp
@@ -178,6 +178,7 @@
         "//frameworks/base/core/tests/bandwidthtests",
         "//frameworks/base/core/tests/benchmarks",
         "//frameworks/base/core/tests/utillib",
+        "//frameworks/base/services/tests/VpnTests",
         "//frameworks/base/tests/vcn",
         "//frameworks/opt/net/ethernet/tests:__subpackages__",
         "//frameworks/opt/telephony/tests/telephonytests",