binder: Add RpcCertificateVerifier.

An interface with a function that verifies a peer certificate.
It is a wrapper over the custom
verify function (see SSL_CTX_set_custom_verify).

Also, RpcTransportCtxFactoryTls::make() requests
an RpcCertificateVerifier.

Bug: 198833574
Test: binderRpcTest
Change-Id: I6e63bc84ede07735baaf8e02fda53a97775c3dcc
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 13ea827..a9bc15d 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -150,6 +150,7 @@
 
     srcs: [
         "binderRpcTest.cpp",
+        "RpcCertificateVerifierSimple.cpp",
     ],
     shared_libs: [
         "libbinder",