Fix memory leak when navigating from native page

- Cordova RTC work item number: 46618
- Apache Cordova Jira issue: https://issues.apache.org/jira/browse/CB-6924
- IBM PMR: 79005,999,000
- Full description: There was a memory leak caused by the PhoneApplicationService in the CordovaView when navigating back and forth between a native and hybrid page.