Throw exception when writing characteristic larger than max attribute

value

In BluetoothGatt.writeCharacteristic(), throw IllegalArgumentException
is longer than max length of an attribute value. The max length of an
attribute value is defined in gatt_api.h as 512, and is used here. CTS
test for this change is linked with the same topic to this CL.

Bug: 286892994
Test: atest CtsBluetoothTestCases
Change-Id: Ie9009922b89403d10546b046346dac7f26d1643e