Android Client: Fix this Static field leak.

Warning Message: ../../src/main/java/org/openmrs/mobile/activities/patientdashboard/PatientDashboardActivity.java:61: Do not place Android context classes in static fields; this is a memory leak

PatientDashboardActivity.java

Fix the above warning message.

Resources:

1. OpenMRS Android Client Github Repository
2. Pull Request Tips
3. Using Git

Submission Steps:

• Fork the OpenMRS Android Client [1] and clone it.
• Open the project in Android Studio and fix the warning.
• Make a Pull Request [2].
• Submit a URL to your Pull Request.