Increase timemout for dumpsys meminfo --unreachable

dumpsys meminfo --unreachable can take longer than 5 seconds,
especially when combined with malloc_debug.  Increase the
timeout to 30 seconds when dumpUnreachable is set.

Bug: 79354139
Test: dumpsys meminfo --unreachable -a
Change-Id: Id1001cbc9dd5123907281e9965d10c0887feb9dc