New TraceUtilsTest

New test for asserting that TraceUtils does not throw an
IllegalArgumentException when passed a long section name. Also,
demonstrate how the public API android.os.Trace.beginSection will throw
an exception if the section name is more than 127 characters long

Also, move TraceUtils to a directory that matches its declared package
name.

Test: atest TraceUtilsTest
Bug: 280850299
Bug: 279715262
Bug: 267482189
Bug: 279784509
Change-Id: I827eb710742d4fabedd4fbb37af64e9ecee118d0