[BUG] Manual code change after generation

Collect manual change need to be done before generation (e.g. due to spec issue, better to fix spec).

Collect manual change need to be done after generation (e.g. due to spec issue, azure core bug, or generator bug).

Cmd line:

```
export SPEC_ROOT=/c/github/azure-rest-api-specs
export AUTOREST_JAVA=/c/github_fork/autorest.java

gulp codegen --projects features --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects policy --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA --preserve
gulp codegen --projects subscriptions --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA --preserve
gulp codegen --projects resources --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA --preserve

gulp codegen --projects storage --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA

gulp codegen --projects keyvault --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA

gulp codegen --projects graphrbac --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects authorization --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA --preserve

gulp codegen --projects msi --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA

gulp codegen --projects network --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects compute --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects appservice --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects containerregistry --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects containerservice --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects containerinstance --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects cosmos --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects dns --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects privatedns --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects monitor --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects sql --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects appplatform --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects redis --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects eventhubs --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects trafficmanager --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects servicebus --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
gulp codegen --projects cdn --spec-root $SPEC_ROOT --autorest-java $AUTOREST_JAVA
```