Add connectivity coverage tests

The coverage tests will allow measuring code coverage for all
Connectivity+Tethering code.

This is a combination of the current TetheringCoverageTests, and
FrameworksNetTests.

Adding min_sdk_version to the test prevents it from using deprecated
IoUtils utilities. Replace it with the non-deprecated alternative.

Test: atest ConnectivityCoverageTests
Change-Id: I5366e1cc9cd6ddb41f24718246381cc2b1cc1383
diff --git a/Tethering/common/TetheringLib/Android.bp b/Tethering/common/TetheringLib/Android.bp
index fce4360..f652772 100644
--- a/Tethering/common/TetheringLib/Android.bp
+++ b/Tethering/common/TetheringLib/Android.bp
@@ -22,6 +22,7 @@
     defaults: ["framework-module-defaults"],
     impl_library_visibility: [
         "//packages/modules/Connectivity/Tethering:__subpackages__",
+        "//packages/modules/Connectivity/tests:__subpackages__",
     ],
 
     srcs: [":framework-tethering-srcs"],