[libgraphicsenv] Add an API to enable profiling features

Set PR_SET_DUMPABLE for process that wishes to
inject Vk/GL layers via metadata. This signals the
graphics driver to enable profiling features.

Bug: 138204026

Test: Add <meta-data android:name="com.android.graphics.injectLayers.enable" android:value="true" />
to the <application> xml in the manifest of a GL/Vk app. Call
prctl(PR_GET_DUMPABLE) in a native app to verify.

Change-Id: Ife7d18f77775499629d830376a76c4599afd9c15