[BUG] Auto created storage account name may be invalid in FunctionAppImpl

[Flanker32]

Describe the bug FunctionAppImpl will auto create storage account with function name as prefix(refers), however, function name may contains "-" and this may be include in the randomName result(refers) which could not be used in storage account name

Exception or Stack Trace

Exception in thread "main" com.microsoft.azure.CloudException: test-appef78792216 is not a valid storage account name. Storage account name must be between 3 and 24 characters in length and use numbers and lower-case letters only.: test-appef78792216 is not a valid storage account name. Storage account name must be between 3 and 24 characters in length and use numbers and lower-case letters only.
    at com.microsoft.azure.AzureClient.createExceptionFromResponse(AzureClient.java:771)
    at com.microsoft.azure.AzureClient.access$100(AzureClient.java:33)
    at com.microsoft.azure.AzureClient$3.call(AzureClient.java:160)
    at com.microsoft.azure.AzureClient$3.call(AzureClient.java:157)
    at rx.internal.operators.OnSubscribeMap$MapSubscriber.onNext(OnSubscribeMap.java:69)
    at retrofit2.adapter.rxjava.CallArbiter.deliverResponse(CallArbiter.java:120)
    at retrofit2.adapter.rxjava.CallArbiter.emitResponse(CallArbiter.java:102)
    at retrofit2.adapter.rxjava.CallExecuteOnSubscribe.call(CallExecuteOnSubscribe.java:46)
    at retrofit2.adapter.rxjava.CallExecuteOnSubscribe.call(CallExecuteOnSubscribe.java:24)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeSingle.call(OnSubscribeSingle.java:81)
    at rx.internal.operators.OnSubscribeSingle.call(OnSubscribeSingle.java:27)
    at rx.internal.operators.SingleToObservable.call(SingleToObservable.java:39)
    at rx.internal.operators.SingleToObservable.call(SingleToObservable.java:27)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.DeferredScalarSubscriber.subscribeTo(DeferredScalarSubscriber.java:153)
    at rx.internal.operators.OnSubscribeTakeLastOne.call(OnSubscribeTakeLastOne.java:32)
    at rx.internal.operators.OnSubscribeTakeLastOne.call(OnSubscribeTakeLastOne.java:22)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
    at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
    at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:41)
    at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:30)
    at rx.Observable.unsafeSubscribe(Observable.java:10327)
    at rx.internal.operators.OperatorSubscribeOn$SubscribeOnSubscriber.call(OperatorSubscribeOn.java:100)
    at rx.internal.schedulers.CachedThreadScheduler$EventLoopWorker$1.call(CachedThreadScheduler.java:230)
    at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: rx.exceptions.OnErrorThrowable$OnNextValue: OnError while emitting onNext value: retrofit2.Response.class
    at rx.exceptions.OnErrorThrowable.addValueAsLastCause(OnErrorThrowable.java:118)
    at rx.internal.operators.OnSubscribeMap$MapSubscriber.onNext(OnSubscribeMap.java:73)
    ... 51 more

To Reproduce Create Function with short name with "-", and will get exception while create Function

Code Snippet SdkContext.randomResourceName("func-test",20) will get result like func-test2ab242005 which contains -

Expected behavior Java SDK should create storage account with valid name while creating new Function App.

Setup (please complete the following information):

• JRE Version: Oracle JDK 1.8.0_241
• SDK Version: 1.36.2

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