ncs: default to newlibc nano

The nano flavour of newlibc used to be the default before NCS v2.2.0.

This changed when the commit in
zephyrproject-rtos/zephyr#51340
was merged downstream, increasing the FLASH size of all nrf9160
samples by about 40KB, due to their requirement on some
variadic C functions whose implementation is much larger
in vanilla newlibc.

This patch reverts the change from upstream and maintains the
newlibc nano flavour as the default for nrf9160 samples,
and all other samples that use newlibc.

Removed decimal point accuracy from cloud codec tests.
The test was introduced while newlibc did not use nano
(and was failing when reintroducing nano).

Signed-off-by: Håvard Vermeer <havard.vermeer@nordicsemi.no>
Signed-off-by: Emanuele Di Santo <emdi@nordicsemi.no>

Kconfig.nrf

@@ -35,6 +35,12 @@ endchoice
 config WARN_EXPERIMENTAL
 	default y
 
+# Zephyr default is newlib and not newlib-nano for consistency between architectures.
+# To reduce FLASH footprint, newlib-nano is preferred default in NCS when newlib is selected.
+config NEWLIB_LIBC_NANO
+	default y
+	depends on NEWLIB_LIBC && HAS_NEWLIB_LIBC_NANO
+
 # This is a temporary solution to whitelist
 # BOARD_THINGY91_NRF9160_NS in compliance
 config BOARD_THINGY91_NRF9160_NS

applications/asset_tracker_v2/tests/nrf_cloud_codec/src/nrf_cloud_codec_test.c

@@ -103,15 +103,15 @@ const static struct cloud_data_battery bat_data_example = {
 	"\"appId\":\"GNSS\","\
 	"\"messageType\":\"DATA\","\
 	"\"ts\":1563968747123,"\
-	"\"data\":{\"lng\":30.03,\"lat\":40.04,\"acc\":180,\"alt\":245,\"spd\":5,\"hdg\":39}"\
+	"\"data\":{\"lng\":30,\"lat\":40,\"acc\":180,\"alt\":245,\"spd\":5,\"hdg\":39}"\
 "}]"
 
 const static struct cloud_data_gnss gnss_data_example = {
 	.queued = true,
 	.gnss_ts = 1563968747123,
 	.pvt = {
-		.longi = 30.03,
-		.lat = 40.04,
+		.longi = 30,
+		.lat = 40,
 		.alt = 245,
 		.acc = 180,
 		.spd = 5,