Add function to change LE Tx Data Length

As part of new SL4A tests for LE CoC to measure data throughput, this
commit adds a function to set the LE Tx Data Length parameter to its
maximum.

Test: Ran the new ACTS Tests for LE CoC (BleCocTest and BleCoc2ConnTest)
Bug: 70683224
Change-Id: Iea93f6cb9f4f7cc484f121afa158d7dae18d1ef1
1 file changed