Only read system/build.prop for properties

otapreopt was trying to read /default.props in order to load default
properties. This file was removed some time ago causing otapreopt to
fail. This change makes it so we only attempt to read the
/system/build.prop file.

Test: Manual OTA of cuttlefish
Bug: 181182967
Change-Id: I8203868b7e68ba8bfd3b80897206a6be247cab92
diff --git a/cmds/installd/otapreopt.cpp b/cmds/installd/otapreopt.cpp
index ef052bd..da39a9d 100644
--- a/cmds/installd/otapreopt.cpp
+++ b/cmds/installd/otapreopt.cpp
@@ -175,8 +175,10 @@
 private:
 
     bool ReadSystemProperties() {
+        // TODO This file does not have a stable format. It should be read by
+        // code shared by init and otapreopt. See b/181182967#comment80
         static constexpr const char* kPropertyFiles[] = {
-                "/default.prop", "/system/build.prop"
+                "/system/build.prop"
         };
 
         for (size_t i = 0; i < arraysize(kPropertyFiles); ++i) {