Add sanitizer tests for musl

Add tests that verify sanitizer behaviors for musl.

Test: sanitize_test.go
Change-Id: I1f0a51cc103ac14d1738cb223e216ee0e32d8550
diff --git a/android/test_config.go b/android/test_config.go
index 70c319a..07ca33d 100644
--- a/android/test_config.go
+++ b/android/test_config.go
@@ -109,7 +109,8 @@
 	config.TestProductVariables.DeviceSecondaryArchVariant = proptools.StringPtr("armv7-a-neon")
 }
 
-func modifyTestConfigForMusl(config Config) {
+// ModifyTestConfigForMusl takes a Config returned by TestConfig and changes the host targets from glibc to musl.
+func ModifyTestConfigForMusl(config Config) {
 	delete(config.Targets, config.BuildOS)
 	config.productVariables.HostMusl = boolPtr(true)
 	determineBuildOS(config.config)