chore(common): Remove unstable flag from AuthorizeCoinJoin.

common/protob/messages-bitcoin.proto

@@ -611,8 +611,6 @@ message OwnershipProof {
  * @next Failure
  */
 message AuthorizeCoinJoin {
-    option (unstable) = true;
-
     required string coordinator = 1;                                    // coordinator identifier to approve as a prefix in commitment data (max. 36 ASCII characters)
     required uint64 max_rounds = 2;                                     // maximum number of rounds that Trezor is authorized to take part in
     required uint32 max_coordinator_fee_rate = 3;                       // maximum coordination fee rate in units of 10^-6 percent

common/protob/messages.proto

@@ -54,7 +54,7 @@ extend google.protobuf.EnumOptions {
 
 /** Options for tagging message types */
 extend google.protobuf.MessageOptions {
-    optional bool unstable = 52001;   // indicate that a message definition might change at any time
+    optional bool unstable = 52001;   // indicate that a message is experimental, intended for development and beta testing only and its definition may change at any time
     optional uint32 wire_type = 52002;   // override wire type specified in the MessageType enum
 }