Upgrade retrofit to 2.10.0

[alishari]

What I have done and why

• Upgrade retrofit to 2.10.0,
• Use retrofit kotlin serialization converter instead of deprecated repo.

How I'm testing it

Do tests pass?

• Run local tests on DemoDebug variant: ./gradlew testDemoDebug
• Check formatting: ./gradlew --init-script gradle/init.gradle.kts spotlessApply

Is this your first pull request?

• Sign the CLA
• Run ./tools/setup.sh
• Import the code formatting style as explained in the setup script.

[Goooler]

Need to remove ProGuard rules

nowinandroid/app/proguard-rules.pro

Lines 11 to 19 in 88c3eb0

	# Fix for Retrofit issue https://github.com/square/retrofit/issues/3751
	# Keep generic signature of Call, Response (R8 full mode strips signatures from non-kept items).
	-keep,allowobfuscation,allowshrinking interface retrofit2.Call
	-keep,allowobfuscation,allowshrinking class retrofit2.Response
	# With R8 full mode generic signatures are stripped for classes that are not
	# kept. Suspend functions are wrapped in continuations where the type argument
	# is used.
	-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation

[Goooler]

Suggested change

	retrofit = "2.10.0"
	retrofit = "2.11.0"