esp32: Increase NimBLE task stack size and overflow detection headroom.

The Python BLE IRQ handler will most likely run on the NimBLE task, so its
C stack must be large enough to accommodate reasonably complicated Python
code (eg a few call depths).  So increase this stack size.

Also increase the headroom from 1024 to 2048 bytes.  This is needed because
(1) the esp32 architecture uses a fair amount of stack in general; and (2)
by the time execution gets to setting the Python stack top via
`mp_stack_set_top()` in this interlock code, about 600 bytes of stack are
already used, which reduces the amount available for Python.

Fixes issue #12349.

Signed-off-by: Damien George <damien@micropython.org>
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index 5dc4a9c..acf0653 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -95,7 +95,7 @@
 #define MICROPY_PY_BLUETOOTH                (1)
 #define MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS (1)
 #define MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS_WITH_INTERLOCK (1)
-#define MICROPY_PY_BLUETOOTH_SYNC_EVENT_STACK_SIZE (CONFIG_BT_NIMBLE_TASK_STACK_SIZE)
+#define MICROPY_PY_BLUETOOTH_SYNC_EVENT_STACK_SIZE (CONFIG_BT_NIMBLE_TASK_STACK_SIZE - 2048)
 #define MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE (1)
 #define MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING (1)
 #define MICROPY_BLUETOOTH_NIMBLE            (1)