Improvements on EnterpriseContactsMultiUserTest.

- Check if feature is supported
- Fails if profile cannot be created
  ...with improved error message
- Start profile when it already exist
- Uses executeShellV2Command() so it properly handles stderr
- Improves logging

Test: atest EnterpriseContactsMultiUserTest#testSecondaryUser_doesNotHaveEnterpriseAccess
Bug: 426019822
Flag: TEST_ONLY

Change-Id: I72e23911f62291a9a72f45f729ff1873493a9442