export setThreadName() and add NULL check

Change-Id: I9b69a23b308fe851ed49722c0da3953433b3f5b8
Set Processes comm name to package name

When debugging audit logs, it is often helpful to
have the packages name. Bear in mind that the
package name is the right most chars up to
TASK_COMM_LEN. Although a possibility of truncation
exists, it can be useful for narrowing down the
possibilities.

Change-Id: Ia735b03f64352d155f8b96e1d47f48e6519b1d4f