parse screenshot invocation event type (#256)

Fix the Android implementation is missing a branch in the `parseInvocationEvent` loop for the `InstabugInvocationEvent.SCREENSHOT` type. It prevents users from using the screenshot invocation on Android React Native apps.

Author: draeton

android/src/main/java/com/instabug/reactlibrary/RNInstabugReactnativePackage.java

@@ -78,6 +78,9 @@ private void parseInvocationEvent(String[] invocationEventValues) {
             } else if (invocationEventValues[i].equals("shake")) {
                 this.invocationEvents.add(InstabugInvocationEvent.SHAKE);
 
+            } else if (invocationEventValues[i].equals("screenshot")) {
+                this.invocationEvents.add(InstabugInvocationEvent.SCREENSHOT);
+
             } else if (invocationEventValues[i].equals("none")) {
                 this.invocationEvents.add(InstabugInvocationEvent.NONE);
             }