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

android/config.go

@@ -1245,6 +1245,10 @@ func (c *deviceConfig) NativeCoverageEnabledForPath(path string) bool {
 	return coverage
 }
 
+func (c *deviceConfig) AfdoAdditionalProfileDirs() []string {
+	return c.config.productVariables.AfdoAdditionalProfileDirs
+}
+
 func (c *deviceConfig) PgoAdditionalProfileDirs() []string {
 	return c.config.productVariables.PgoAdditionalProfileDirs
 }