ANDROID: gki_config: enable CONFIG_IIO_TRIGGERED_BUFFER

Enable CONFIG_IIO_TRIGGERED_BUFFER to support more IIO APIs for
IIO device drivers.

Since CONFIG_IIO_TRIGGERED_BUFFER will select CONFIG_IIO_TRIGGER,
I replace CONFIG_IIO_TRIGGER with CONFIG_IIO_TRIGGERED_BUFFER
instead of adding CONFIG_IIO_TRIGGERED_BUFFER in defconfig.
Otherwise "build_abi.sh --update" will report error of defconfig.

Bug: 271373845
Change-Id: I2843ccddd10e32b867f2ecfb0f8e312b127f36d5
Signed-off-by: Yingying Tang <quic_yintang@quicinc.com>