Refactor for Better Resource Management

The GraphicsEnvironment/GraphicsEnv code is being refactored to allow
for better resource management related to open files and file
descriptors and reducing the amount of times the rules files are parsed.

This is also laying the groundwork for other modules to query if ANGLE
will be loaded or not, for example to display a dialog box to the user
when ANGLE is selected for an app.

Bug: 120910315
Test: Verify CtsAngleIntegrationHostTestCases passes.
Change-Id: If985df7d84d043942d5eccdc575a53cb2a08a0ba