Do not assume order of quotas dictionary elements

This fixes the quotas db unit test that breaks with a randomized PYTHONHASHSEED
(see the bug report).

The test assumed that the quotas dictionary from plugin.get_all_quotas() had
elements in a particular order. Found with PYTHONHASHSEED=1235130571.

The fix refactors the test case to handle an unsorted quotas dictionary. Also
choose some different quota limits to make it clearer what is being verified.

Partial-bug: #1348818

Note: There are several other unrelated unit tests that also break with a
randomized PYTHONHASHSEED, but they are not addressed here. They will be
addressed in separate patches.

Change-Id: I3892b51082629e6ebce175f64f501717741baa37
Merge "Do not assume order of quotas dictionary elements"