fix(@angular/build): fully disable component style HMR in JIT mode

The component stylesheet HMR functionality requires build-time analysis
of each component by the AOT compiler to provide the needed information
to identify initial styles and detect individual changes to each style.
Part of the style HMR rebuild logic was unintentionally enabled in JIT
mode. The initial load of the application operated correctly but subsequent
changes to file-based stylesheets were delayed by one rebuild cycle. To
avoid this misalignment, all component stylesheet HMR functionality is
now disabled when in JIT mode.

(cherry picked from commit 9921271)

Author: clydin

packages/angular/build/src/builders/application/options.ts

@@ -381,7 +381,7 @@ export async function normalizeOptions(
   // Initial options to keep
   const {
     allowedCommonJsDependencies,
-    aot,
+    aot = true,
     baseHref,
     crossOrigin,
     externalDependencies,
@@ -469,7 +469,7 @@ export async function normalizeOptions(
     clearScreen,
     define,
     partialSSRBuild: usePartialSsrBuild || partialSSRBuild,
-    externalRuntimeStyles,
+    externalRuntimeStyles: aot && externalRuntimeStyles,
     instrumentForCoverage,
     security,
     templateUpdates: !!options.templateUpdates,