Adding ApexInfo utility

This is to get name/version when the HAL is started from an APEX. This
is the initial work and just prints name/version on startup.

Bug: 268439003
Test: adb logcat | grep com.google.android.widevine
Change-Id: I756c042d544f973999738f7d17022d916b9712cd

libwvdrmengine/apex/Android.bp

@@ -74,6 +74,11 @@ apex {
     ],
     binaries: ["android.hardware.drm-service.widevine"],
     file_contexts: "file_contexts",
+    // TODO(b/268439003) We need an API to get apex version. Until then
+    // we'll read apex_manifest.pb to get the version. To label apex_manifest.pb
+    // as vendor_configs_file (which the apex can access), turn off force-label.
+    use_file_contexts_as_is: true,
+
     use_vndk_as_stable: true,
     updatable: false,