Update language to comply with inclusive guidance

Update android_app_set to use word install rather than master for
android_app_sets, this better matches the phrasing used for apex_set.

See https://source.android.com/setup/contribute/respectful-code for
reference

Bug: 161896447
Test: m nothing
Change-Id: I429e7f8b16c42c10ad4d9543110f5ce814a893b1
diff --git a/java/app_test.go b/java/app_test.go
index d4323bb..efb4fd2 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -161,11 +161,11 @@
 		t.Errorf("wrong partition value: '%s', expected 'system'", s)
 	}
 	mkEntries := android.AndroidMkEntriesForTest(t, config, "", module.Module())[0]
-	actualMaster := mkEntries.EntryMap["LOCAL_APK_SET_MASTER_FILE"]
-	expectedMaster := []string{"foo.apk"}
-	if !reflect.DeepEqual(actualMaster, expectedMaster) {
-		t.Errorf("Unexpected LOCAL_APK_SET_MASTER_FILE value: '%s', expected: '%s',",
-			actualMaster, expectedMaster)
+	actualInstallFile := mkEntries.EntryMap["LOCAL_APK_SET_INSTALL_FILE"]
+	expectedInstallFile := []string{"foo.apk"}
+	if !reflect.DeepEqual(actualInstallFile, expectedInstallFile) {
+		t.Errorf("Unexpected LOCAL_APK_SET_INSTALL_FILE value: '%s', expected: '%s',",
+			actualInstallFile, expectedInstallFile)
 	}
 }