Add the missing qRegisterProtobufTypes call to tests

qRegisterProtobufTypes needs to be called explicitly if test never
uses methods that call qRegisterProtobufTypes implicitly.

Change-Id: I98552ed6ca364a7620c69d4fdd3d84a635d318c0
Reviewed-by: Konrad Kujawa <konrad.kujawa@qt.io>
Reviewed-by: Tatiana Borisova <tatiana.borisova@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit c2eabf1726)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/protobuf/basic/tst_protobuf_basictypes.cpp

@@ -18,6 +18,10 @@ class QtProtobufTypesGenerationTest : public QObject
 {
     Q_OBJECT
 private slots:
+    void initTestCase()
+    {
+        qRegisterProtobufTypes();
+    }
     void EmptyMessageTest();
     void BoolMessageTest();
     void IntMessageTest();

tests/auto/protobuf/basic/tst_protobuf_maptypes.cpp

@@ -17,6 +17,10 @@ class QtProtobufMapTypesGenerationTest : public QObject
 {
     Q_OBJECT
 private slots:
+    void initTestCase()
+    {
+        qRegisterProtobufTypes();
+    }
     void SInt32StringMapMessageTest();
     void StringStringMapMessageTest();
 

tests/auto/protobuf/basic/tst_protobuf_repeatedtypes.cpp

@@ -15,6 +15,10 @@ class QtProtobufRepeatedTypesGenerationTest : public QObject
 {
     Q_OBJECT
 private slots:
+    void initTestCase()
+    {
+        qRegisterProtobufTypes();
+    }
     void RepeatedStringMessageTest();
     void RepeatedIntMessageTest();
     void RepeatedDoubleMessageTest();