Report 3072-bit Certificate Capability

(This is a merge of go/wvgerrit/23154)

This patch updates the ClientCapabilities protobuf to match the latest
on the server side and adds plumbing to the provisioning request
process so that devices can report whether they like big certs.

Their capacity to lie remains untested.

Bug: 34076937
Test: license_unittest
Change-Id: I3bcc9f1741146953d8bc0ff3d7d2305e7ac2c118

libwvdrmengine/cdm/core/src/license_protocol.proto

@@ -510,6 +510,11 @@ message ClientIdentification {
       HDCP_NO_DIGITAL_OUTPUT = 0xff;
     }
 
+    enum CertificateKeyType {
+      RSA_2048 = 0;
+      RSA_3072 = 1;
+    }
+
     optional bool client_token = 1 [default = false];
     optional bool session_token = 2 [default = false];
     optional bool video_resolution_constraints = 3 [default = false];
@@ -524,6 +529,7 @@ message ClientIdentification {
     // A device may have SRM data, and report a version, but may not be capable
     // of updating SRM data.
     optional bool can_update_srm = 8 [default = false];
+    repeated CertificateKeyType supported_certificate_key_type = 9;
   }
 
   // Type of factory-provisioned device root of trust. Optional.