Add ANR traces to their own zip entries.

These files can be very large (O(20k) lines), so it makes more sense to
add them to their own zip entry.

Since this change could break tools that are expecting that section,
it's only enabled when setting the dumpstate version to 2.0-dev-1:

adb shell setprop dumpstate.version 2.0-dev-1

Test: DumpstateTest passes; manual verification
Bug: 32470528
Bug: 32064548

Change-Id: I4726b2209b15722c22defa87bffb24dc633d5bcd