Use TARGET_RECOVERY_PRE_COMMAND before calling __reboot() recovery

For the Power menu,
frameworks/base/core/jni/android_os_Power.cpp#L180
already uses TARGET_RECOVERY_PRE_COMMAND if
TARGET_RECOVERY_PRE_COMMAND is defined in the
BoardConfig.mk for a device to make a system() call before
calling __reboot() for recovery. This commit adds
the same thing to the other places that we know we are
getting into recovery using __reboot().

Change-Id: Ifd0394fed1e87b63d80d95e0e2a049004518e27e
diff --git a/extendedcommands.c b/extendedcommands.c
index d263405..e5daa5a 100644
--- a/extendedcommands.c
+++ b/extendedcommands.c
@@ -875,6 +875,9 @@
         switch (chosen_item)
         {
             case 0:
+#ifdef TARGET_RECOVERY_PRE_COMMAND
+                __system( TARGET_RECOVERY_PRE_COMMAND );
+#endif
                 __reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, "recovery");
                 break;
             case 1: