docs: use inject() and bootstrapApplication in dialog, snack-bar, and bottom-sheet docs

[yogeshwaran-c]

What kind of change does this PR introduce?

Documentation update.

What is the current behavior?

The dialog, snack-bar, and bottom-sheet docs use outdated patterns:

• Constructor injection with @Inject(TOKEN) for data injection tokens
• Constructor injection for DialogRef / MatDialogRef
• @NgModule provider blocks for default options
• Relative import paths like '../dialog' instead of package paths

Relates to #32709

What is the new behavior?

• Replace constructor injection with inject() function
• Replace @Inject(TOKEN) with inject<Type>(TOKEN)
• Replace @NgModule provider blocks with bootstrapApplication
• Fix import paths to use proper package paths (@angular/material/dialog,
  @angular/material/snack-bar, @angular/material/bottom-sheet,
  @angular/cdk/dialog)
• Update prose from "root module" to "app config"

Files changed

File	Changes
src/cdk/dialog/dialog.md	DialogRef constructor -> inject(), @Inject(DIALOG_DATA) -> inject(), @NgModule -> bootstrapApplication
src/material/dialog/dialog.md	MatDialogRef constructor -> inject(), @Inject(MAT_DIALOG_DATA) -> inject(), @NgModule -> bootstrapApplication, fix import path
src/material/snack-bar/snack-bar.md	@Inject(MAT_SNACK_BAR_DATA) -> inject(), @NgModule -> bootstrapApplication, fix import path
src/material/bottom-sheet/bottom-sheet.md	@Inject(MAT_BOTTOM_SHEET_DATA) -> inject(), @NgModule -> bootstrapApplication, fix import path