Add device and SIM to AccountTypeManager

This makes these account types available throughout the app rather than
just the Nav drawer.

Test:
Added unit tests for new classes; run with:
$ adb shell am instrument -w \
  com.google.android.tests/android.test.InstrumentationTestRunner

Manually on Nexus 6, LG G5 and Samsung S7 with device and SIM contacts
in CP2 by verifying "Device" and "SIM" options were available in
* nav drawer
* account list accessed by Pressing FAB without default account set
* editor account dropdown for new contact
* editor account label  when editing existing contact
* picker for default account in settings
* settings customize screen account list

Bug 30867780

Change-Id: I329381ccc58d59f2e27f65a3d9dc0164fb20c971
diff --git a/res/values/colors.xml b/res/values/colors.xml
index e8d1f54..771ba44 100644
--- a/res/values/colors.xml
+++ b/res/values/colors.xml
@@ -254,4 +254,7 @@
 
     <!-- Primary text color in Contacts app -->
     <color name="contacts_text_color">#333333</color>
+
+    <!-- tint color for device account icons -->
+    <color name="device_account_tint_color">#7f7f7f</color>
 </resources>