Minijail: add kernel-style-based .clang-format file.

Based on http://clang.llvm.org/docs/ClangFormatStyleOptions.html

Running clang-format on the entire Minijail codebase suggests
a few changes, but individual code sections can use this format
just fine.

Bug: None
Change-Id: I8067b2a0e200697064a0c17c9c8042d785bea92c
diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..a3ef233
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,6 @@
+BasedOnStyle: LLVM
+IndentWidth: 8
+UseTab: Always
+BreakBeforeBraces: Linux
+AllowShortIfStatementsOnASingleLine: false
+IndentCaseLabels: false