Revert "Revert "Modify symlink_forest to rerun when soong_build has changed.""

This reverts commit aa5cc2cd6af5da7c65914500fc6e11c6a130060c.

Reason for revert: Fixed the bug in the original draft.
There was an error in how we compared the file's MTime to the
file's contents.

Bug: 300288299
Test: presubmits
Test: build/soong/tests/run_integration_tests.sh

Change-Id: I9e53432c0842c0b9fc13fe20d30ce9af37640c7f
diff --git a/tests/run_integration_tests.sh b/tests/run_integration_tests.sh
index 223baa4..8045591 100755
--- a/tests/run_integration_tests.sh
+++ b/tests/run_integration_tests.sh
@@ -10,6 +10,7 @@
 "$TOP/build/soong/tests/persistent_bazel_test.sh"
 "$TOP/build/soong/tests/soong_test.sh"
 "$TOP/build/soong/tests/stale_metrics_files_test.sh"
+"$TOP/build/soong/tests/symlink_forest_rerun_test.sh"
 "$TOP/prebuilts/build-tools/linux-x86/bin/py3-cmd" "$TOP/build/bazel/ci/rbc_dashboard.py" aosp_arm64-userdebug
 
 # The following tests build against the full source tree and don't rely on the