Revert "scripts: strip_package: Use install mask from python"

This reverts commit 8c9ec1cd001b2c4eea218751b6b7788286f3674a.

Reason for revert: cros deploy failed by "Cannot strip packages
Reason for revert: release builder failure (b/241716391) may be also related.

Original change's description:
> scripts: strip_package: Use install mask from python
>
> Use install mask defined in python file instead of common.sh
>
> BUG=b:241001394
> TEST=cros deploy localhost:9222 libdbus-sys
>
> Change-Id: I533cbfd4498768dcad03e7513ec792dd9dd980dd
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3803792
> Tested-by: Ram Chandrasekar <rchandrasekar@google.com>
> Reviewed-by: Mike Frysinger <vapier@chromium.org>
> Auto-Submit: Ram Chandrasekar <rchandrasekar@google.com>
> Commit-Queue: Ram Chandrasekar <rchandrasekar@google.com>

Bug=b:241001394
Bug=b:241716391

Change-Id: I4312df75bf99fcf6ff0e745d359599fd955edf30
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3812765
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Zubin Mithra <zsm@chromium.org>
Commit-Queue: Zubin Mithra <zsm@chromium.org>
Owners-Override: Zubin Mithra <zsm@chromium.org>
diff --git a/scripts/strip_package.py b/scripts/strip_package.py
index 43d6f9c..a16cf78 100644
--- a/scripts/strip_package.py
+++ b/scripts/strip_package.py
@@ -10,8 +10,9 @@
 
 from chromite.lib import build_target_lib
 from chromite.lib import commandline
+from chromite.lib import constants
 from chromite.lib import cros_build_lib
-from chromite.lib import install_mask
+from chromite.lib import osutils
 
 
 # The builder module lives in the devserver path.
@@ -20,6 +21,8 @@
 import builder
 
 
+_DEFAULT_MASK = 'DEFAULT_INSTALL_MASK'
+
 def create_parser() -> commandline.ArgumentParser:
   """Creates the cmdline argparser, populates the options and description."""
   parser = commandline.ArgumentParser(description=__doc__)
@@ -44,6 +47,19 @@
   return parser
 
 
+def populate_install_mask() -> bool:
+  """Extract the default install mask and populate the local environment."""
+  env_var_value = osutils.SourceEnvironment(
+      os.path.join(constants.CROSUTILS_DIR, 'common.sh'),
+      [_DEFAULT_MASK],
+      multiline=True)
+
+  if _DEFAULT_MASK not in env_var_value:
+    return False
+  os.environ[_DEFAULT_MASK] = env_var_value[_DEFAULT_MASK]
+  return True
+
+
 def main(argv: List[str]) -> int:
   """Main function."""
   cros_build_lib.AssertInsideChroot()
@@ -56,9 +72,8 @@
   else:
     sysroot = build_target_lib.get_default_sysroot_path(options.board)
 
-  os.environ['DEFAULT_INSTALL_MASK'] = '\n'.join(
-      install_mask.DEFAULT_INSTALL_MASK)
-
+  if not populate_install_mask():
+    return False
   if not builder.UpdateGmergeBinhost(sysroot, options.packages, options.deep):
     return 1
   return 0