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ARROW-7491: [Java] Improve the performance of aligning

Aligning is an important and frequent operation when writing IPC data. It writes no more than 7 0 bytes to the output.
The current implementation creates a new byte array each time, leading to performance overhead, and increases the GC pressure.

We improve it by means of a shared byte array. Benchmark evaluation shows a 11% performance gain.

Closes #6120 from liyafan82/fly_1230_ali and squashes the following commits:

d337a2de5 <liyafan82>  Make buffer array members final
9bd08b91d <liyafan82>  Improve writeZeros method
3db4eaf7e <liyafan82>  Avoid creating byte arrays repeatedly when writing integers
cc241fb09 <liyafan82>  Improve the performance of aligning

Authored-by: liyafan82 <fan_li_ya@foxmail.com>
Signed-off-by: Wes McKinney <wesm+git@apache.org>