releasetools: Remove deprecated BOARD_BUILD_SYSTEM_ROOT_IMAGE

This variable is always false or empty now, so clean up remaining
references to the variable.

Bug: 241346584
Test: Presubmit
Change-Id: I5dd3d356729d0bd2639633580bbb85f8b03582cf
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 8ce6083..63fd854 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1156,8 +1156,7 @@
     return self.build_props.get(prop)
 
 
-def LoadRecoveryFSTab(read_helper, fstab_version, recovery_fstab_path,
-                      system_root_image=False):
+def LoadRecoveryFSTab(read_helper, fstab_version, recovery_fstab_path):
   class Partition(object):
     def __init__(self, mount_point, fs_type, device, length, context, slotselect):
       self.mount_point = mount_point
@@ -1216,12 +1215,6 @@
                                device=pieces[0], length=length, context=context,
                                slotselect=slotselect)
 
-  # / is used for the system mount point when the root directory is included in
-  # system. Other areas assume system is always at "/system" so point /system
-  # at /.
-  if system_root_image:
-    assert '/system' not in d and '/' in d
-    d["/system"] = d["/"]
   return d
 
 
@@ -1237,22 +1230,19 @@
   # ../RAMDISK/system/etc/recovery.fstab. This function has to handle both
   # cases, since it may load the info_dict from an old build (e.g. when
   # generating incremental OTAs from that build).
-  system_root_image = info_dict.get('system_root_image') == 'true'
   if info_dict.get('no_recovery') != 'true':
     recovery_fstab_path = 'RECOVERY/RAMDISK/system/etc/recovery.fstab'
     if not DoesInputFileContain(input_file, recovery_fstab_path):
       recovery_fstab_path = 'RECOVERY/RAMDISK/etc/recovery.fstab'
     return LoadRecoveryFSTab(
-        read_helper, info_dict['fstab_version'], recovery_fstab_path,
-        system_root_image)
+        read_helper, info_dict['fstab_version'], recovery_fstab_path)
 
   if info_dict.get('recovery_as_boot') == 'true':
     recovery_fstab_path = 'BOOT/RAMDISK/system/etc/recovery.fstab'
     if not DoesInputFileContain(input_file, recovery_fstab_path):
       recovery_fstab_path = 'BOOT/RAMDISK/etc/recovery.fstab'
     return LoadRecoveryFSTab(
-        read_helper, info_dict['fstab_version'], recovery_fstab_path,
-        system_root_image)
+        read_helper, info_dict['fstab_version'], recovery_fstab_path)
 
   return None
 
@@ -1980,11 +1970,6 @@
   if info_dict.get("gki_boot_image_without_ramdisk") == "true":
     return False  # A GKI boot.img has no ramdisk since Android-13.
 
-  if info_dict.get("system_root_image") == "true":
-    # The ramdisk content is merged into the system.img, so there is NO
-    # ramdisk in the boot.img or boot-<kernel version>.img.
-    return False
-
   if info_dict.get("init_boot") == "true":
     # The ramdisk is moved to the init_boot.img, so there is NO
     # ramdisk in the boot.img or boot-<kernel version>.img.
@@ -3853,14 +3838,11 @@
     output_sink(recovery_img_path, recovery_img.data)
 
   else:
-    system_root_image = info_dict.get("system_root_image") == "true"
     include_recovery_dtbo = info_dict.get("include_recovery_dtbo") == "true"
     include_recovery_acpio = info_dict.get("include_recovery_acpio") == "true"
     path = os.path.join(input_dir, recovery_resource_dat_path)
-    # With system-root-image, boot and recovery images will have mismatching
-    # entries (only recovery has the ramdisk entry) (Bug: 72731506). Use bsdiff
-    # to handle such a case.
-    if system_root_image or include_recovery_dtbo or include_recovery_acpio:
+    # Use bsdiff to handle mismatching entries (Bug: 72731506)
+    if include_recovery_dtbo or include_recovery_acpio:
       diff_program = ["bsdiff"]
       bonus_args = ""
       assert not os.path.exists(path)