Add a way to disable the spec-mandated 2-minute floor on OTA retries.

[bzbarsky-apple]

This makes unit testing of OTA providers take a lot less time.

Fixes #25922

[github-actions]

PR #25925: Size comparison from 12072b3 to 43065a2

Increases (5 builds for nrfconnect, qpg)

platform	target	config	section	12072b3	43065a2	change	% change
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	(read/write)	1174112	1174124	12	0.0
			rodata	132640	132652	12	0.0
	all-clusters-minimal-app	nrf52840dk_nrf52840	(read/write)	1119184	1119196	12	0.0
			rodata	109456	109468	12	0.0
	all-clusters-app	nrf7002dk_nrf5340_cpuapp	text	776072	776076	4	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1152960	1152968	8	0.0
			.text	600056	600064	8	0.0
	lock-app	qpg6105+debug	(read/write)	1121536	1121552	16	0.0
			.text	568636	568652	16	0.0

Decreases (2 builds for cc32xx, nrfconnect)

platform	target	config	section	12072b3	43065a2	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL	.debug_info	20310331	20310330	-1	-0.0
nrfconnect	all-clusters-minimal-app	nrf52840dk_nrf52840	text	774368	774364	-4	-0.0

Full report (7 builds for cc32xx, mbed, nrfconnect, qpg)

platform	target	config	section	12072b3	43065a2	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	645825	645825	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	933102	933102	0	0.0
			.debug_aranges	87704	87704	0	0.0
			.debug_frame	301596	301596	0	0.0
			.debug_info	20310331	20310330	-1	-0.0
			.debug_line	2681125	2681125	0	0.0
			.debug_loc	2827568	2827568	0	0.0
			.debug_ranges	286448	286448	0	0.0
			.debug_str	3041144	3041144	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	105953	105953	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	380543	380543	0	0.0
			.symtab	257472	257472	0	0.0
			.text	537752	537752	0	0.0
mbed	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2466536	2466536	0	0.0
			.bss	215964	215964	0	0.0
			.data	5880	5880	0	0.0
			.text	1429180	1429180	0	0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1174112	1174124	12	0.0
			bss	155557	155557	0	0.0
			rodata	132640	132652	12	0.0
			text	805156	805156	0	0.0
	all-clusters-minimal-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1119184	1119196	12	0.0
			bss	154713	154713	0	0.0
			rodata	109456	109468	12	0.0
			text	774368	774364	-4	-0.0
	all-clusters-app	nrf7002dk_nrf5340_cpuapp	(read only)	4	4	0	0.0
			(read/write)	1434148	1434148	0	0.0
			bss	135297	135297	0	0.0
			rodata	228692	228692	0	0.0
			text	776072	776076	4	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1152960	1152968	8	0.0
			.bss	96036	96036	0	0.0
			.data	852	852	0	0.0
			.text	600056	600064	8	0.0
	lock-app	qpg6105+debug	(read/write)	1121536	1121552	16	0.0
			.bss	91172	91172	0	0.0
			.data	856	856	0	0.0
			.text	568636	568652	16	0.0