Fix JNI error in tv-app

[amitnj]

Fixes #25330

Change default passcode returned from account login cluster. Move use of JniUtfString in a code block so that ReleaseStringUTFChars does not happen after DeleteLocalRef.

[github-actions]

PR #25331: Size comparison from 3b80154 to a9515dc

Increases (2 builds for nrfconnect, qpg)

platform	target	config	section	3b80154	a9515dc	change	% change
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	text	807924	807928	4	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1151284	1151292	8	0.0
			.text	598380	598388	8	0.0

Decreases (1 build for nrfconnect)

platform	target	config	section	3b80154	a9515dc	change	% change
nrfconnect	all-clusters-minimal-app	nrf52840dk_nrf52840	text	777072	777068	-4	-0.0

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

platform	target	config	section	3b80154	a9515dc	change	% change
cc32xx	lock	CC3235SF_LAUNCHXL		0	0	0	0.0
			(read only)	642609	642609	0	0.0
			(read/write)	203672	203672	0	0.0
			.ARM.attributes	44	44	0	0.0
			.ARM.exidx	8	8	0	0.0
			.bss	197072	197072	0	0.0
			.comment	194	194	0	0.0
			.data	1480	1480	0	0.0
			.debug_abbrev	930077	930077	0	0.0
			.debug_aranges	87280	87280	0	0.0
			.debug_frame	299816	299816	0	0.0
			.debug_info	20256038	20256038	0	0.0
			.debug_line	2655900	2655900	0	0.0
			.debug_loc	2797195	2797195	0	0.0
			.debug_ranges	281768	281768	0	0.0
			.debug_str	3023188	3023188	0	0.0
			.ramVecs	780	780	0	0.0
			.resetVecs	64	64	0	0.0
			.rodata	105761	105761	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	377825	377825	0	0.0
			.symtab	256224	256224	0	0.0
			.text	534724	534724	0	0.0
mbed	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2467096	2467096	0	0.0
			.bss	215788	215788	0	0.0
			.data	5880	5880	0	0.0
			.text	1429740	1429740	0	0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1167376	1167376	0	0.0
			bss	143423	143423	0	0.0
			rodata	136188	136188	0	0.0
			text	807924	807928	4	0.0
	all-clusters-minimal-app	nrf52840dk_nrf52840	(read only)	4	4	0	0.0
			(read/write)	1112396	1112396	0	0.0
			bss	142579	142579	0	0.0
			rodata	113032	113032	0	0.0
			text	777072	777068	-4	-0.0
	all-clusters-app	nrf7002dk_nrf5340_cpuapp	(read only)	4	4	0	0.0
			(read/write)	1372476	1372476	0	0.0
			bss	105886	105886	0	0.0
			rodata	213576	213576	0	0.0
			text	767508	767508	0	0.0
qpg	lighting-app	qpg6105+debug	(read/write)	1151284	1151292	8	0.0
			.bss	99804	99804	0	0.0
			.data	852	852	0	0.0
			.text	598380	598388	8	0.0
	lock-app	qpg6105+debug	(read/write)	1118500	1118500	0	0.0
			.bss	96292	96292	0	0.0
			.data	864	864	0	0.0
			.text	565600	565600	0	0.0