Use correct includes for mixed build gen headers

Previously, genrules which were used as generated_headers only
propagated the old Soong gen directory as an include path, even if the
genrule was managed by Bazel. With this chance, the gen directory of the
Baze output files are used in mixed-build mode.

Test: USE_BAZEL_ANALYSIS=1 m libc
Test: m libc
Change-Id: I3913c4e5b0354421ba1fe43d1f6ef4d1e729a058
diff --git a/android/bazel.go b/android/bazel.go
index 51ff3cb..3fb34c7 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -169,7 +169,6 @@
 		"liblinker_debuggerd_stub",      // ruperts@, cc_library_static, depends on //system/libbase
 		"libbionic_tests_headers_posix", // ruperts@, cc_library_static
 		"libc_dns",                      // ruperts@, cc_library_static
-		"generated_android_ids",         // cparsons@, genrule
 		"note_memtag_heap_async",        // cparsons@, cc_library_static
 		"note_memtag_heap_sync",         // cparsons@, cc_library_static
 	}
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 5d438ea..d07b002 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -229,11 +229,16 @@
 	filePaths, ok := bazelCtx.GetOutputFiles(label, ctx.Arch().ArchType)
 	if ok {
 		var bazelOutputFiles android.Paths
+		exportIncludeDirs := map[string]bool{}
 		for _, bazelOutputFile := range filePaths {
 			bazelOutputFiles = append(bazelOutputFiles, android.PathForBazelOut(ctx, bazelOutputFile))
+			exportIncludeDirs[filepath.Dir(bazelOutputFile)] = true
 		}
 		c.outputFiles = bazelOutputFiles
 		c.outputDeps = bazelOutputFiles
+		for includePath, _ := range exportIncludeDirs {
+			c.exportedIncludeDirs = append(c.exportedIncludeDirs, android.PathForBazelOut(ctx, includePath))
+		}
 	}
 	return ok
 }