fix(ble/bluedroid): Prevent esp_ble_gatts_send_indicate() with value_len > 512 (IDFGH-13782)

[nebkat]

Description

BLE indications are limited by max attribute length (512) and also by MTU size - 3 (see https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-54/out/en/host/attribute-protocol--att-.html#UUID-fd156898-28db-9cd8-e6e1-94d0278d0d1c).

Checking for MTU size is the user's responsibility, however an easy mistake is to chunk data by MTU size - 3 only. At the maximum MTU size of 517 results in 514, which is greater than 512, and causes heap corruption due to a buffer overflow.

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