AOSP/Calendar - Minimal calendar app.

+ Calendar UI shows day/week/month calendars.
+ Calendar can be scrolled different days/weeks/months
+ Clicking on day icon shows the today.
+ New events can not be created.
+ Fixed the tests so that they pass.
+ Deleted src/com/android/calendar/AbstractCalendarActivity.java and tested
  everything.

Bug: 118760450
Bug: 118712914

Test: manual - Ran the following CTS tests on Pixel phone. Tested the calendar UI.
$ adb shell am instrument -w com.android.calendar.tests
  com.android.calendar.FormatDateRangeTest:.
  com.android.calendar.UtilsTests:..................
  com.android.calendar.WeekNumberTest:.
  com.android.calendar.widget.CalendarAppWidgetServiceTest:..
  Test results for InstrumentationTestRunner=......................
  Time: 0.315
  OK (22 tests)

+ android.provider.cts.CalendarTest:................................
  Time: 17.842
  OK (32 tests)
+ android.content.cts.AvailableIntentsTest:.................................
  Time: 0.441
  OK (33 tests)
+ com.android.cts.privilegedupdate.PrivilegedUpdateTest:...
  Time: 0.119
  OK (3 tests)
+ android.permission2.cts.ProtectedBroadcastsTest:..
  Time: 0.285
  OK (2 tests)

Change-Id: Ib6a3df46e46619248d2e45d71622109d3085eb64