camput: predictably-failing disabled deadlock test

Change-Id: Ibf0877ac1b4e32ad32fe9592c487915130f9f488
camput: limit upload concurrency (number of goroutines)

Use separate workers for directory uploads.
Limit upload concurrency to 3+2+3 (normal+directories+stat)
goroutines on Android, and 10+5+10 otherwise.

Change-Id: Idac4c94b7d7ec4fc6c6a77fed111e0ece0843545