otautil: Factor out the utils that're private to recovery.

A number of utility functions are intended for serving recovery's own
use. Exposing them via libotautil (which is a static lib) would pass the
dependencies onto libotautil's users (e.g. recovery image, updater, host
simulator, device-specific recovery UI/updater extensions etc). This CL
finds a new home for the utils that are private to recovery.

Test: mmma bootable/recovery
Change-Id: I575e97ad099b85fe1c1c8c7c9458a5a43d4e11e1
diff --git a/install/fuse_install.cpp b/install/fuse_install.cpp
index 8a7a278..143b5d3 100644
--- a/install/fuse_install.cpp
+++ b/install/fuse_install.cpp
@@ -37,7 +37,7 @@
 #include "fuse_provider.h"
 #include "fuse_sideload.h"
 #include "install/install.h"
-#include "otautil/roots.h"
+#include "recovery_utils/roots.h"
 
 static constexpr const char* SDCARD_ROOT = "/sdcard";
 // How long (in seconds) we wait for the fuse-provided package file to