Rename VcnUnderlyingNetworkPrioirty to VcnUnderlyingNetworkTemplate

Rename the classes' names as well as the test files.

Bug: 206044122
Test: atest FrameworksVcnTests, CtsVcnTestCases
Change-Id: I19d13acf0e46921a7254a39dff2af332c36ab2b2
11 files changed