Create helper method for sandbox tests, transform existing tests into using it.

This CL should not change the test functionality (in one test I changed where some out-of-execroot files live).

RELNOTES: None.
PiperOrigin-RevId: 358794463

Author: larsrc-google

src/test/java/com/google/devtools/build/lib/BUILD

@@ -585,6 +585,7 @@ java_test(
         "//src/main/java/com/google/devtools/build/lib/worker",
         "//src/main/java/com/google/devtools/common/options:options_internal",
         "//src/main/protobuf:worker_protocol_java_proto",
+        "//src/test/java/com/google/devtools/build/lib/actions/util",
         "//src/test/java/com/google/devtools/build/lib/events:testutil",
         "//src/test/java/com/google/devtools/build/lib/testutil",
         "//src/test/java/com/google/devtools/build/lib/testutil:JunitUtils",