Created another hawkBit app example that demonstrates theme

custimization.

Signed-off-by: Kai Zimmermann <kai.zimmermann@bosch-si.com>

hawkbit-repository/pom.xml

@@ -67,6 +67,10 @@
          <groupId>org.hibernate</groupId>
          <artifactId>hibernate-validator</artifactId>
       </dependency>
+      <dependency>
+         <groupId>javax.validation</groupId>
+         <artifactId>validation-api</artifactId>
+      </dependency>
       <dependency>
          <groupId>com.google.guava</groupId>
          <artifactId>guava</artifactId>