Add build flags for legacy EROFS support.

EROFS images by default will only work on newer kernels. Old versions of
5.4 and 4.19 need an extra flag to mkfs.erofs.

Add BUILD_EROFS_USE_LEGACY_COMPRESSION to force this flag.

Bug: 222373106
Test: build with BUILD_EROFS_USE_LEGACY_COMPRESSION enabled
Change-Id: I3818e14356beaa11073c6b9fea6a6ad999bba4aa

tools/releasetools/build_image.py

@@ -348,6 +348,8 @@ def BuildImageMkfs(in_dir, prop_dict, out_file, target_out, fs_config):
       build_command.extend(["-C", prop_dict["erofs_pcluster_size"]])
     if "erofs_share_dup_blocks" in prop_dict:
       build_command.extend(["--chunksize", "4096"])
+    if "erofs_use_legacy_compression" in prop_dict:
+      build_command.extend(["-E", "legacy-compress"])
 
     build_command.extend([out_file, in_dir])
     if "erofs_sparse_flag" in prop_dict and not disable_sparse:
@@ -653,6 +655,7 @@ def ImagePropFromGlobalDict(glob_dict, mount_point):
       "erofs_pcluster_size",
       "erofs_share_dup_blocks",
       "erofs_sparse_flag",
+      "erofs_use_legacy_compression",
       "squashfs_sparse_flag",
       "system_f2fs_compress",
       "system_f2fs_sldc_flags",
@@ -698,6 +701,7 @@ def ImagePropFromGlobalDict(glob_dict, mount_point):
       (True, "avb_{}_hashtree_enable", "avb_hashtree_enable"),
       (True, "avb_{}_key_path", "avb_key_path"),
       (True, "avb_{}_salt", "avb_salt"),
+      (True, "erofs_use_legacy_compression", "erofs_use_legacy_compression"),
       (True, "ext4_share_dup_blocks", "ext4_share_dup_blocks"),
       (True, "{}_base_fs_file", "base_fs_file"),
       (True, "{}_disable_sparse", "disable_sparse"),