Improve soong stuck ninja detection output

Add -T to the pstree command so that it doesn't print the threads of
the running processes, the thread information hasn't been useful for
debugging any previous instances of stuck processes.

Log that there are stuck processes to stdout with a pointer to look
in soong.log.

Test: manual
Change-Id: I6459f2887a7e79591e8c451d06969f8709db3393