Start using some dagger 2

Early days as we start migration, so lots of duplication between
Dependency and dagger2, but can be removed when migration is done.

Test: existing tests.
Change-Id: I00c3da6ebbd46a26e512d8a7aa1e2b828e08f33f
diff --git a/packages/SystemUI/proguard.flags b/packages/SystemUI/proguard.flags
index ee94aed..cc6848f 100644
--- a/packages/SystemUI/proguard.flags
+++ b/packages/SystemUI/proguard.flags
@@ -17,6 +17,7 @@
 -keep class com.android.systemui.car.CarSystemUIFactory
 -keep class com.android.systemui.SystemUIFactory
 -keep class * extends com.android.systemui.SystemUI
+-keep class * implements com.android.systemui.SystemUI$Injector
 
 -keepclasseswithmembers class * {
     public <init>(android.content.Context, android.util.AttributeSet);