Fatal error on insufficient resource to use Goma in Soong UI.

As suggested in
https://android-review.googlesource.com/c/platform/build/soong/+/839293


I am moving some features in goma.mk to goma.go in Soong UI.

With this CL, let me implement ulimit check to Soong UI.

Test: export USE_GOMA=true
Test: launch aosp_arm-eng
Test: make
Test: the command succeeds if "ulimit -n" and "ulimit -u" are large enough.
Test: Otherwise, it shows error.  I confirmed both cases.
Change-Id: I5d7d5ed71f620302a0d635770d1a51a2baab51fd
Signed-off-by: Yoshisato Yanagisawa <yyanagisawa@google.com>