clang-format derive_sdk

Indent to two spaces and move some includes around. This seems to be the
standard for most cpp code.

Also set up a preupload hook to enforce the code remains in this style.

Test: presubmit
Change-Id: I7e0e50480118d393ae2a0e12c8a62dcd1b30aedd
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
new file mode 100644
index 0000000..65c2b62
--- /dev/null
+++ b/PREUPLOAD.cfg
@@ -0,0 +1,7 @@
+[Builtin Hooks]
+clang_format = true
+commit_msg_changeid_field = true
+commit_msg_test_field = true
+
+[Builtin Hooks Options]
+clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp