Fix pre-Lollipop (21) Android debug

Namely, automatically pick debug over Wi-Fi for devices with an older release and debug over USB otherwise.

A message is printed both in editor output window and console (uppercase here) to let the user know about what mechanism is being used and why.

platform/android/export/export.cpp

@@ -1073,7 +1073,11 @@ public:
 		//export_temp
 		ep.step("Exporting APK", 0);
 
-		p_debug_flags |= DEBUG_FLAG_REMOTE_DEBUG_LOCALHOST;
+		const bool use_remote = (p_debug_flags & DEBUG_FLAG_REMOTE_DEBUG) || (p_debug_flags & DEBUG_FLAG_DUMB_CLIENT);
+		const bool use_reverse = devices[p_device].api_level >= 21;
+
+		if (use_reverse)
+			p_debug_flags |= DEBUG_FLAG_REMOTE_DEBUG_LOCALHOST;
 
 		String export_to = EditorSettings::get_singleton()->get_settings_path() + "/tmp/tmpexport.apk";
 		Error err = export_project(p_preset, true, export_to, p_debug_flags);
@@ -1119,40 +1123,54 @@ public:
 			return ERR_CANT_CREATE;
 		}
 
-		if (p_debug_flags & DEBUG_FLAG_REMOTE_DEBUG) {
+		if (use_remote) {
+			if (use_reverse) {
 
-			args.clear();
-			args.push_back("-s");
-			args.push_back(devices[p_device].id);
-			args.push_back("reverse");
-			args.push_back("--remove-all");
-			OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
+				static const char *const msg = "** Device API >= 21; debugging over USB **";
+				EditorNode::get_singleton()->get_log()->add_message(msg);
+				print_line(String(msg).to_upper());
 
-			int dbg_port = EditorSettings::get_singleton()->get("network/debug/remote_port");
-			args.clear();
-			args.push_back("-s");
-			args.push_back(devices[p_device].id);
-			args.push_back("reverse");
-			args.push_back("tcp:" + itos(dbg_port));
-			args.push_back("tcp:" + itos(dbg_port));
+				args.clear();
+				args.push_back("-s");
+				args.push_back(devices[p_device].id);
+				args.push_back("reverse");
+				args.push_back("--remove-all");
+				OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
 
-			OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
-			print_line("Reverse result: " + itos(rv));
-		}
+				if (p_debug_flags & DEBUG_FLAG_REMOTE_DEBUG) {
 
-		if (p_debug_flags & DEBUG_FLAG_DUMB_CLIENT) {
+					int dbg_port = EditorSettings::get_singleton()->get("network/debug/remote_port");
+					args.clear();
+					args.push_back("-s");
+					args.push_back(devices[p_device].id);
+					args.push_back("reverse");
+					args.push_back("tcp:" + itos(dbg_port));
+					args.push_back("tcp:" + itos(dbg_port));
 
-			int fs_port = EditorSettings::get_singleton()->get("filesystem/file_server/port");
+					OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
+					print_line("Reverse result: " + itos(rv));
+				}
 
-			args.clear();
-			args.push_back("-s");
-			args.push_back(devices[p_device].id);
-			args.push_back("reverse");
-			args.push_back("tcp:" + itos(fs_port));
-			args.push_back("tcp:" + itos(fs_port));
+				if (p_debug_flags & DEBUG_FLAG_DUMB_CLIENT) {
 
-			err = OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
-			print_line("Reverse result2: " + itos(rv));
+					int fs_port = EditorSettings::get_singleton()->get("filesystem/file_server/port");
+
+					args.clear();
+					args.push_back("-s");
+					args.push_back(devices[p_device].id);
+					args.push_back("reverse");
+					args.push_back("tcp:" + itos(fs_port));
+					args.push_back("tcp:" + itos(fs_port));
+
+					err = OS::get_singleton()->execute(adb, args, true, NULL, NULL, &rv);
+					print_line("Reverse result2: " + itos(rv));
+				}
+			} else {
+
+				static const char *const msg = "** Device API < 21; debugging over Wi-Fi **";
+				EditorNode::get_singleton()->get_log()->add_message(msg);
+				print_line(String(msg).to_upper());
+			}
 		}
 
 		ep.step("Running on Device..", 3);