Further clarify failure message.

An invalid IP for which the test commonly fails ends with '.', which could
have been misread as part of the sentence. This CL adds quotes around the
quoted IP String to clarify where it starts/ends. It also adds a '.' to
the end of the sentence.

Bug: 115960287
Test: Treehugger
Change-Id: If3ed6d090221079d76ff25845269aa2b30317188
1 file changed