Android: fix mobule-install scripts for Python 3

Fixes https://github.com/bazelbuild/bazel/issues/7580

Closes #7581.

PiperOrigin-RevId: 236595349
diff --git a/tools/android/incremental_install.py b/tools/android/incremental_install.py
index 0638c1b..d7b9c48 100644
--- a/tools/android/incremental_install.py
+++ b/tools/android/incremental_install.py
@@ -173,6 +173,8 @@
 
     # Check these first so that the more specific error gets raised instead of
     # the more generic AdbError.
+    stdout = stdout.decode()
+    stderr = stderr.decode()
     if "device not found" in stderr:
       raise DeviceNotFoundError()
     elif "device unauthorized" in stderr:
diff --git a/tools/android/stubify_manifest.py b/tools/android/stubify_manifest.py
index d07287e..f2e8a48 100644
--- a/tools/android/stubify_manifest.py
+++ b/tools/android/stubify_manifest.py
@@ -151,7 +151,7 @@
       output_xml.write(new_manifest)
 
     with open(FLAGS.output_datafile, "wb") as output_file:
-      output_file.write("\n".join([old_application, app_package]))
+      output_file.write("\n".join([old_application, app_package]).encode())
 
   elif FLAGS.mode == "instant_run":
     with open(FLAGS.input_manifest, "rb") as input_manifest: