Call resetServices() when setting globals in tests

Call resetServices() when setting globals in tests

Now that resetServices() will preserve (but reset) customized services,
it should be reasonably safe to call it every time globals are changed,
and much more effective than relying on tests to call it every time
themselves.

Depends-On: Iab8ea3a61bbc6803805d855ef23c071067646f71
Depends-On: I00e35ecea6a27468674b2a6e7d9d9eb6518e3bd5
Change-Id: Ie7a89f6ed7d52a0bc01672019ff92e7ee105a1f3