Fix URLConnection test cases.

- Have Support_TestWebServer send down an explicit timezone so
  there's no ambiguity in the parse. HttpURLConnection coerces all
  timezones into GMT.
- getFileNameMap always constructs a new FileNameMap if the default
  is null. This implies that setFileNameMap(null) now sets things back
  to the default.
- getRequestProperty / setRequestProperty on URLConnection subclasses
  that don't override those methods behave as if they were backed by
  a map.

bug: 26023804
Change-Id: I75abd114f0dcbd8afbfa1786b7d5142e0b071bed
3 files changed