recovery: replacing fs_mgr_read_fstab() with new fs_mgr APIs

The fstab settings of early-mounted partitions (e.g., /vendor) will be in
kernel device tree. Switch to the new API to get the whole settings with
those in device tree:

    fs_mgr_read_fstab_with_dt("/etc/recovery.fstab")

The original default /fstab.{ro.hardware} might be moved to
/vendor/etc/. or /odm/etc/. Use another new API to get the default fstab
instead of using the hard-coded /fstab.{ro.hardware}. This API also
includes the settings from device tree:

    fs_mgr_read_fstab_default()

Bug: 35811655
Test: boot sailfish recovery
Change-Id: Iaa56ac7f7b4c4dfc7180c65f03e9a37b94f1de09
diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp
index a06384d..07d183b 100644
--- a/uncrypt/uncrypt.cpp
+++ b/uncrypt/uncrypt.cpp
@@ -163,20 +163,9 @@
 }
 
 static struct fstab* read_fstab() {
-    fstab = NULL;
-
-    // The fstab path is always "/fstab.${ro.hardware}".
-    std::string ro_hardware = android::base::GetProperty("ro.hardware", "");
-    if (ro_hardware.empty()) {
-        LOG(ERROR) << "failed to get ro.hardware";
-        return NULL;
-    }
-
-    std::string fstab_path = "/fstab." + ro_hardware;
-
-    fstab = fs_mgr_read_fstab(fstab_path.c_str());
+    fstab = fs_mgr_read_fstab_default();
     if (!fstab) {
-        LOG(ERROR) << "failed to read " << fstab_path;
+        LOG(ERROR) << "failed to read default fstab";
         return NULL;
     }