Lint detector for ColorStateLists that use app:alpha without android:alpha

Detection + quick fix + a new module for showing all available
AppCompat Lint rules

Bug: 146350188
Test: ./gradlew :lint-demos:lint-demo-appcompat:lint
Change-Id: I5def996beebe4d9f054044957eb4aaf1f7eb489e
diff --git a/settings.gradle b/settings.gradle
index d2ff5f2..7a80011 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -161,6 +161,7 @@
 includeProject(":lifecycle:lifecycle-viewmodel", "lifecycle/lifecycle-viewmodel")
 includeProject(":lifecycle:lifecycle-viewmodel-ktx", "lifecycle/lifecycle-viewmodel-ktx")
 includeProject(":lifecycle:lifecycle-viewmodel-savedstate","lifecycle/lifecycle-viewmodel-savedstate")
+includeProject(":lint-demos:lint-demo-appcompat", "lint-demos/lint-demo-appcompat")
 includeProject(":loader:loader", "loader/loader")
 includeProject(":loader:loader-ktx", "loader/loader-ktx")
 includeProject(":localbroadcastmanager:localbroadcastmanager", "localbroadcastmanager/localbroadcastmanager")