fix(BridgeSession): add more bits to the id

Adds more bits to the conference ID which should reduce the chances for
a conflict.

Author: paweldomas

src/main/java/org/jitsi/jicofo/JitsiMeetConferenceImpl.java

@@ -2603,7 +2603,7 @@ class BridgeSession
          */
         final String id
             = JitsiMeetConferenceImpl.this.id
-                    + "_" +Integer.toHexString(RANDOM.nextInt(0x1_0000));
+                    + "_" +Integer.toHexString(RANDOM.nextInt(0x1_000000));
 
         /**
          * The list of participants in the conference which use this