Add fastboot mode to recovery

Add a fastboot mode to recovery that can be
entered with command line args or with the ui.

Add usb property triggers to switch between
fastboot and adb configurations.

Allow switching between fastboot and adb through
usb commands by opening a unix socket. adbd/fastbootd
writes to this socket, which interrupts the ui and
switches to the new mode.

Test: Use fastboot mode
Bug: 78793464
Change-Id: I7891bb84427ec734a21a872036629b95ab3fb13c
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
new file mode 100644
index 0000000..53a2adc
--- /dev/null
+++ b/fastboot/fastboot.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "device.h"
+
+Device::BuiltinAction StartFastboot(Device* device, const std::vector<std::string>& args);