Chip-tool hits the Code is unsafe/racy assert when BLE commissioning is started.

[jmartinez-silabs]

PR #26180 added assert on the task ownership of the chip Stack lock on some SystemLayer timer calls.

The Linux bleManagerImpl starts a SystemLayer timer on the BLE connection which now asserts.

This pr fix the assert on SystemLayer().StartTimer call by acquiring the chipStack Lock before the call (and releasing it after)

Tested the fix by successfully completing the commissioning with chip-tool on a raspi.

[github-actions]

PR #26200: Size comparison from 65f075c to 84d2b66

Increases (1 build for cc32xx)

platform	target	config	section	65f075c	84d2b66	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL	.debug_info	20330829	20330830	1	0.0

Full report (1 build for cc32xx)

platform	target	config	section	65f075c	84d2b66	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	643249	643249	0	0.0
			(read/write)	203848	203848	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197248	197248	0	0.0
			.comment	194	194	0	0.0
			.data	1480	1480	0	0.0
			.debug_abbrev	933224	933224	0	0.0
			.debug_aranges	87792	87792	0	0.0
			.debug_frame	302140	302140	0	0.0
			.debug_info	20330829	20330830	1	0.0
			.debug_line	2687904	2687904	0	0.0
			.debug_loc	2838960	2838960	0	0.0
			.debug_ranges	288072	288072	0	0.0
			.debug_str	3042335	3042335	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	104401	104401	0	0.0
			.shstrtab	232	232	0	0.0
			.stab	204	204	0	0.0
			.stabstr	441	441	0	0.0
			.stack	2048	2048	0	0.0
			.strtab	377963	377963	0	0.0
			.symtab	256976	256976	0	0.0
			.text	536728	536728	0	0.0