Upgrade to 2.2.1

Upgrade bitflags crate to version 2.2.1.
Tests are removed because they depend on another crate which has
currently not been imported to Android.

Test: Build
Change-Id: I2cdb005d4902f6a95a8e90ac2565acfd604c5af9
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..790ac5b
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,13 @@
+# Security Policy
+
+## Supported Versions
+
+Security updates are applied only to the latest release.
+
+## Reporting a Vulnerability
+
+If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released.
+
+Please disclose it at [security advisory](https://github.com/bitflags/bitflags/security/advisories/new).
+
+This project is maintained by a team of volunteers on a reasonable-effort basis. As such, please give us at least 90 days to work on a fix before public exposure.