Handle interaction of Bundle.hasFileDescriptors() with removal

Removing entries from a Bundle may change its has-FDs state, so now
induce a recheck after removals.  In support of that, make the
recheck set the known state in all cases, not just in the has-FDs
case; and note that filterValues() inherently produces a result that
is known to have no FDs.

Bug 26676151

Change-Id: Ida07b77ad2046aeafb98e0b164cd571ce45d064f