Load default prop from /system/etc/prop.default

/default.prop is moved to /system/etc/prop.default for full Treblized
devices. Modifies property_service to load it from there first.
In recovery mode, the file is renamed as /prop.default. This path is
tried if /system/etc/prop.default is not available.

Bug: 37815285
Test: Tested with ag/2419001. Booted pixel phones, checked the location
      of prop.default, verified the symlink at /default.prop, checked a
      few properties via adb shell and manually tested a few apps.
      Booted to recovery and ran 'adb sideload' successfully.
Change-Id: I485231f21fc86b0aec58edf867e229a31e77d85e
Merged-In: I485231f21fc86b0aec58edf867e229a31e77d85e
(cherry-picked from 527d80d945e7b53e53bcc4d42900b3bce228f5d1)
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 0af6c21..b7907e5 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -517,7 +517,7 @@
     }
 }
 
-static void load_properties_from_file(const char *, const char *);
+static bool load_properties_from_file(const char *, const char *);
 
 /*
  * Filter is used to decide which properties to load: NULL loads all keys,
@@ -581,17 +581,18 @@
 
 // Filter is used to decide which properties to load: NULL loads all keys,
 // "ro.foo.*" is a prefix match, and "ro.foo.bar" is an exact match.
-static void load_properties_from_file(const char* filename, const char* filter) {
+static bool load_properties_from_file(const char* filename, const char* filter) {
     Timer t;
     std::string data;
     std::string err;
     if (!ReadFile(filename, &data, &err)) {
         PLOG(WARNING) << "Couldn't load property file: " << err;
-        return;
+        return false;
     }
     data.push_back('\n');
     load_properties(&data[0], filter);
     LOG(VERBOSE) << "(Loading properties from " << filename << " took " << t << ".)";
+    return true;
 }
 
 static void load_persistent_properties() {
@@ -666,7 +667,13 @@
 }
 
 void property_load_boot_defaults() {
-    load_properties_from_file("/default.prop", NULL);
+    if (!load_properties_from_file("/system/etc/prop.default", NULL)) {
+        // Try recovery path
+        if (!load_properties_from_file("/prop.default", NULL)) {
+            // Try legacy path
+            load_properties_from_file("/default.prop", NULL);
+        }
+    }
     load_properties_from_file("/odm/default.prop", NULL);
     load_properties_from_file("/vendor/default.prop", NULL);
 
diff --git a/libcutils/fs_config.cpp b/libcutils/fs_config.cpp
index 221dea2..c39071c 100644
--- a/libcutils/fs_config.cpp
+++ b/libcutils/fs_config.cpp
@@ -134,7 +134,8 @@
     { 00640, AID_ROOT,      AID_SHELL,     0, "data/nativetest64/tests.txt" },
     { 00750, AID_ROOT,      AID_SHELL,     0, "data/nativetest/*" },
     { 00750, AID_ROOT,      AID_SHELL,     0, "data/nativetest64/*" },
-    { 00600, AID_ROOT,      AID_ROOT,      0, "default.prop" },
+    { 00600, AID_ROOT,      AID_ROOT,      0, "default.prop" }, // legacy
+    { 00600, AID_ROOT,      AID_ROOT,      0, "system/etc/prop.default" },
     { 00600, AID_ROOT,      AID_ROOT,      0, "odm/build.prop" },
     { 00600, AID_ROOT,      AID_ROOT,      0, "odm/default.prop" },
     { 00444, AID_ROOT,      AID_ROOT,      0, odm_conf_dir + 1 },