Teach clang-format the right import statement order.

Taken from
https://source.android.com/docs/setup/contribute/code-style#order-import-statements.

#codehealth

Test: clang-format on http://ag/20333208
Change-Id: I1378293bbc0a6b7a3482f9bd0beb71f95e11809d
1 file changed