logd: continue search out-of-order entries timestamp tail

Regression from commit 8e8e8db5

For liblogcat reader -t or -T <timestamp> tail requests, continue
search for pertinent out-of-order entries for an additional 30 seconds
back into logging history to find a more inclusive starting point.

For example, if you have an out of order landing like
[..., 3, 6, 1, 8, 2, 5] and ask for 3 you used to get only 5, and now
you get 3, 6, 8, 5 as 'expected'

Test: gTest liblog-unit-tests logd-unit-tests logcat-unit-tests
Bug: 35373582
Change-Id: I2a0732933fa371aed383d49c8d48d01f33db2a79