ProjectExplorer: Make BuildStepConfigWidget::displayName a value

Use BuildStep::displayName() as default.

This probably could be the only possibility, but currently there
are some discrepancies that are kept in this patch to make
the patch mechanical.

Change-Id: I2a1e5c2ff37ad95e25309eb16e07099e42191f60
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/android/androidpackageinstallationstep.cpp

@@ -128,6 +128,7 @@ namespace Internal {
 AndroidPackageInstallationStepWidget::AndroidPackageInstallationStepWidget(AndroidPackageInstallationStep *step)
     : BuildStepConfigWidget(step, false)
 {
+    setDisplayName(tr("Make install"));
 }
 
 QString AndroidPackageInstallationStepWidget::summaryText() const
@@ -135,11 +136,6 @@ QString AndroidPackageInstallationStepWidget::summaryText() const
     return "<b>" + tr("Make install") + "</b>";
 }
 
-QString AndroidPackageInstallationStepWidget::displayName() const
-{
-    return tr("Make install");
-}
-
 //
 // AndroidPackageInstallationStepFactory
 //