Move dump() to dumpAsync(), more oneway calls.

When calling out to dump services hosted by external apps, use
dumpAsync() to avoid hanging if the remote process is wedged.

Test: builds, boots, runs with minimal logs triggered
Bug: 32715088
Change-Id: I70aa2666ae21dae8f09ded2063bed359c0b210c5
Merged-In: I70aa2666ae21dae8f09ded2063bed359c0b210c5