Set min_sdk_version of framework-connectivity-b to 36

VCN will be moved to Tethering module from Android B. Thus
setting the min_sdk_version to 36

Bug: 390096003
Test: atest FrameworkVcnTests && atest CtsVcnTestCases
Test: Enable VCN in mainline, sideload module and
      run mts-user -m CtsStrictJavaPackagesTestCases on AP3A
Flag: EXEMPT; bug fix
Change-Id: I427b2e0231e2ccdc870500399be9387036b14edc