allow for custom app version to be set (#397)

* add custom app version

* gitignore

Author: e7mac

.gitignore

@@ -182,3 +182,4 @@ captures/
 ## CUSTOM
 
 Release/
+*/out.map

AndroidSDKCore/src/main/java/com/leanplum/Leanplum.java

@@ -102,6 +102,7 @@ public class Leanplum {
   private static RegisterDeviceFinishedCallback registerDeviceFinishedHandler;
   private static LeanplumDeviceIdMode deviceIdMode = LeanplumDeviceIdMode.MD5_MAC_ADDRESS;
   private static String customDeviceId;
+  private static String customAppVersion = null;
   private static boolean userSpecifiedDeviceId;
   private static boolean initializedMessageTemplates = false;
   private static boolean locationCollectionEnabled = true;
@@ -281,6 +282,16 @@ public static boolean isScreenTrackingEnabled() {
     return LeanplumInternal.getIsScreenTrackingEnabled();
   }
 
+  /**
+   * By default, Leanplum reports the version of your app using
+   * getPackageManager().getPackageInfo, which can be used for reporting and targeting
+   * on the Leanplum dashboard. If you wish to use any other string as the version,
+   * you can call this before your call to Leanplum.start()
+   */
+  public static void setAppVersion(String appVersion) {
+    customAppVersion = appVersion;
+  }
+
   /**
    * Sets the type of device ID to use. Default: {@link LeanplumDeviceIdMode#MD5_MAC_ADDRESS}
    */
@@ -634,6 +645,9 @@ private static void startHelper(
 
     // Setup parameters.
     String versionName = Util.getVersionName();
+    if (customAppVersion != null) {
+      versionName = customAppVersion;
+    }
     if (versionName == null) {
       versionName = "";
     }