Honor maven user-settings file for mta build (#663)

Allow setting custom settings file for maven in mta build, which is for example required if a custom maven repo (i.e. company internal) needs to be used.

test/groovy/MtaBuildTest.groovy

@@ -181,6 +181,14 @@ public class MtaBuildTest extends BasePiperTest {
         assert 'something' == dockerExecuteRule.dockerParams.dockerOptions
     }
 
+    @Test
+    void canConfigureMavenUserSettings() {
+
+        stepRule.step.mtaBuild(script: nullScript, projectSettingsFile: 'settings.xml')
+
+        assert shellRule.shell.find(){ c -> c.contains('cp settings.xml $HOME/.m2/settings.xml')}
+    }
+
     @Test
     void buildTargetFromDefaultStepConfigurationTest() {
 

vars/mtaBuild.groovy

@@ -26,7 +26,9 @@ import groovy.transform.Field
      * The location of the SAP Multitarget Application Archive Builder jar file, including file name and extension.
      * If it is not provided, the SAP Multitarget Application Archive Builder is expected on PATH.
      */
-    'mtaJarLocation'
+    'mtaJarLocation',
+    /** Path or url to the mvn settings file that should be used as project settings file.*/
+    'projectSettingsFile'
 ]
 @Field Set PARAMETER_KEYS = STEP_CONFIG_KEYS.plus([
     /** @see dockerExecute */
@@ -59,6 +61,12 @@ void call(Map parameters = [:]) {
 
         dockerExecute(script: script, dockerImage: configuration.dockerImage, dockerOptions: configuration.dockerOptions) {
 
+            // Apply maven user-settings (for custom repositories, etc)
+            if (configuration.projectSettingsFile) {
+                sh 'mkdir -p $HOME/.m2'
+                sh "cp ${configuration.projectSettingsFile} \$HOME/.m2/settings.xml"
+            }
+
             def mtaYamlName = "mta.yaml"
             def applicationName = configuration.applicationName