dashboard: add Android trybots

Updates golang/go#23824

Change-Id: I6386bc267c35856858b3e46d0998fb60e3406e02
Reviewed-on: https://go-review.googlesource.com/c/build/+/172798
Reviewed-by: Elias Naur <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: bradfitz

dashboard/builders.go

@@ -1989,11 +1989,12 @@ func init() {
 		},
 	})
 	addBuilder(BuildConfig{
-		Name:     "android-amd64-emu",
-		HostType: "host-android-amd64-emu",
-		Notes:    "Android emulator on GCE",
+		Name:              "android-amd64-emu",
+		HostType:          "host-android-amd64-emu",
+		Notes:             "Android emulator on GCE",
+		numTryTestHelpers: 3,
 		tryBot: func(repo, branch, goBranch string) bool {
-			return repo == "mobile" && atLeastGo1(branch, 13) && atLeastGo1(goBranch, 13)
+			return (repo == "go" || repo == "mobile") && atLeastGo1(branch, 13) && atLeastGo1(goBranch, 13)
 		},
 		buildsRepo: func(repo, branch, goBranch string) bool {
 			switch repo {

dashboard/builders_test.go

@@ -83,6 +83,7 @@ func TestTrybots(t *testing.T) {
 			repo:   "go",
 			branch: "master",
 			want: []string{
+				"android-amd64-emu",
 				"freebsd-amd64-12_0",
 				"js-wasm",
 				"linux-386",
@@ -277,7 +278,7 @@ func TestBuilderConfig(t *testing.T) {
 		{b("[email protected]", "net"), none},
 
 		// The mobile repo requires Go 1.13+.
-		{b("android-amd64-emu", "go"), onlyPost},
+		{b("android-amd64-emu", "go"), both},
 		{b("android-amd64-emu", "mobile"), both},
 		{b("android-amd64-emu", "[email protected]"), none},
 		{b("android-amd64-emu", "[email protected]"), none},