Categorize sysprop header file as android repo header in .clang-format

Test: Formats the C++ as expected.
Bug: 177678702

Change-Id: I2886dafaee6d6ff48575e489d5dfb02340fd6013
Merged-In: I2886dafaee6d6ff48575e489d5dfb02340fd6013
(cherry picked from commit 76f718600ea968d6cde07f3e3ae6ab143296deeb)
diff --git a/.clang-format b/.clang-format
index 3380a2a..30e9eda 100644
--- a/.clang-format
+++ b/.clang-format
@@ -31,7 +31,7 @@
     Priority:        3
   - Regex:           '^<[[:alnum:]_]+>'
     Priority:        4
-  - Regex:           '^<.*/[[:alnum:]_]+\.h>'
+  - Regex:           '^<.*/[[:alnum:]_]+\.h>$|^<[[:alnum:]_]+\.sysprop\.h>$'
     Priority:        2
   - Regex:           '^".*'
     Priority:        1