Add persistent GWP-ASan sysprops.

Adds persistent sysprops for test infra usage, and adds the tests for
the sysprops.

The test does some fancy flocking in order to restore any existing
GWP-ASan sysprop usage in the test cleanup.

Bug: 236738714
Test: atest bionic-unit-tests
Ignore-AOSP-First: cherry-pick to internal branch
Change-Id: I8956296d39c98ce8c7dd0a703b240530d8ad48db
Merged-In: I8956296d39c98ce8c7dd0a703b240530d8ad48db
diff --git a/tests/utils.h b/tests/utils.h
index 72214c2..81869e3 100644
--- a/tests/utils.h
+++ b/tests/utils.h
@@ -19,6 +19,7 @@
 #include <dirent.h>
 #include <dlfcn.h>
 #include <fcntl.h>
+#include <gtest/gtest.h>
 #include <inttypes.h>
 #include <sys/mman.h>
 #include <sys/prctl.h>
@@ -264,6 +265,7 @@
 };
 
 void RunGwpAsanTest(const char* test_name);
+void RunSubtestNoEnv(const char* test_name);
 #endif
 
 class FdLeakChecker {