PackageSignatures: Add close bracket for "past signatures" output.

Test: dumpsys package shows ']', whereas it did not before.
Change-Id: I7575d78cda28f723ef5c2b1e37db21652318a6da

services/core/java/com/android/server/pm/PackageSignatures.java

@@ -318,7 +318,7 @@ class PackageSignatures {
                         mSigningDetails.signatures[i].hashCode()));
             }
         }
-        buf.append("]}");
+        buf.append("]");
         buf.append(", past signatures:[");
         if (mSigningDetails.pastSigningCertificates != null) {
             for (int i = 0; i < mSigningDetails.pastSigningCertificates.length; i++) {
@@ -329,6 +329,7 @@ class PackageSignatures {
                 buf.append(Integer.toHexString(mSigningDetails.pastSigningCertificatesFlags[i]));
             }
         }
+        buf.append("]}");
         return buf.toString();
     }
 }