Demo app crashes when searching patient which has invalid date.

[santosh-pingle]

Describe the bug

Demo app get crashed when it parse invalid date of the patient in the PatientListViewModel.

Process: com.google.android.fhir.demo, PID: 27356
                                                                                                    java.time.format.DateTimeParseException: Text '1966' could not be parsed at index 4
                                                                                                    	at java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:2050)
                                                                                                    	at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1952)
                                                                                                    	at java.time.LocalDate.parse(LocalDate.java:425)
                                                                                                    	at com.google.android.fhir.demo.PatientListViewModelKt.toPatientItem(PatientListViewModel.kt:186)
                                                                                                    	at com.google.android.fhir.demo.PatientListViewModel.getSearchResults(PatientListViewModel.kt:104)
                                                                                                    	at com.google.android.fhir.demo.PatientListViewModel.access$getSearchResults(PatientListViewModel.kt:40)
                                                                                                    	at com.google.android.fhir.demo.PatientListViewModel$getSearchResults$1.invokeSuspend(Unknown Source:15)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
                                                                                                    	at android.os.Handler.handleCallback(Handler.java:942)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                                                    	at android.os.Looper.loopOnce(Looper.java:240)
                                                                                                    	at android.os.Looper.loop(Looper.java:351)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:8423)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:584)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1013)
                                                                                                    	Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@6e6ca8a, Dispatchers.Main.immediate]

val dob =
   if (hasBirthDateElement()) {
     LocalDate.parse(birthDateElement.valueAsString, DateTimeFormatter.ISO_DATE)
   } else {
     null
   }

Component
reference app

To Reproduce
Steps to reproduce the behavior:

1. Open demo app.
2. Sync patients resources from HAPI FHIR Test server by clicking one time sync or periodic sync, patients get downloaded.
3. Open search patients screen.
4. Start typing 't', app exists.

Expected behavior
App should not exit.
Just catch the exception, and set the null or default value.

Screenshots
If applicable, add screenshots to help explain your problem.

Smartphone (please complete the following information):

• Device: Pixel4a emulator
• Android version: Android 12
• Build number:
• Version