Introduce afdo

A new configuration rule for sampling PGO. This differs from the
original pgo.go rule in the following ways:
 * Automatic propagation to static dependencies
 * Simpler configuration (just put `afdo: true` to optimsation targets)

http://go/android-afdo

Test: build
Bug: 79161490
Change-Id: Ie194824cd523bca19e10ced41d2078fc598f13b3
diff --git a/android/config.go b/android/config.go
index 5c0e5ae..0187a8a 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1245,6 +1245,10 @@
 	return coverage
 }
 
+func (c *deviceConfig) AfdoAdditionalProfileDirs() []string {
+	return c.config.productVariables.AfdoAdditionalProfileDirs
+}
+
 func (c *deviceConfig) PgoAdditionalProfileDirs() []string {
 	return c.config.productVariables.PgoAdditionalProfileDirs
 }