
Previously we use tab spaces for indent in java and c sources, while we use 4 spaces for indent in python sources, but it is sometimes confusing. This patch expands all tab spaces to 4 spaces, to use 4 spaces for general way to indent. Bonus: This patch also removes trailing white spaces. Change-Id: I1b9e7688d606c0da1bc015b1a4d396d19f4dc18a