trace: Make sure saved_tgids array is resized

Kernel bug causes saved_tgids to be overwritten. Resize saved_tgids when
resize is requested to avoid memory corruption.

Bug: 62669736

Change-Id: I9157506c9d835b9dae854595a1d7ef5b2fb3967d
Signed-off-by: Joel Fernandes <joelaf@google.com>