[RenderEngine] Organize RenderEngine directory.

This patch:
1. adds proper namespace renderengine to all RenderEngine code,
   and namespace gl to all GLES related code
2. creates gl/ directory for GLES backend code
3. Reorder include header files, remove unused header files.

BUG: 112585051
Test: Build, flash, run display validation
Change-Id: I81f0b8831213607cde08562958f7c38ddaf4c9e6
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 888dd38..2787132 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -618,9 +618,10 @@
 
     // Get a RenderEngine for the given display / config (can't fail)
     int32_t renderEngineFeature = 0;
-    renderEngineFeature |= (useColorManagement ? RE::RenderEngine::USE_COLOR_MANAGEMENT : 0);
-    getBE().mRenderEngine =
-            RE::impl::RenderEngine::create(HAL_PIXEL_FORMAT_RGBA_8888, renderEngineFeature);
+    renderEngineFeature |= (useColorManagement ?
+                            renderengine::RenderEngine::USE_COLOR_MANAGEMENT : 0);
+    getBE().mRenderEngine = renderengine::impl::RenderEngine::create(HAL_PIXEL_FORMAT_RGBA_8888,
+                                                                      renderEngineFeature);
     LOG_ALWAYS_FATAL_IF(getBE().mRenderEngine == nullptr, "couldn't create RenderEngine");
 
     LOG_ALWAYS_FATAL_IF(mVrFlingerRequestsDisplay,
@@ -2420,7 +2421,7 @@
     /*
      * Create our display's surface
      */
-    std::unique_ptr<RE::Surface> renderSurface = getRenderEngine().createSurface();
+    std::unique_ptr<renderengine::Surface> renderSurface = getRenderEngine().createSurface();
     renderSurface->setCritical(state.type == DisplayDevice::DISPLAY_PRIMARY);
     renderSurface->setAsync(state.isVirtual());
     renderSurface->setNativeWindow(nativeWindow.get());
@@ -5458,7 +5459,7 @@
 
     // this binds the given EGLImage as a framebuffer for the
     // duration of this scope.
-    RE::BindNativeBufferAsFramebuffer bufferBond(getRenderEngine(), buffer);
+    renderengine::BindNativeBufferAsFramebuffer bufferBond(getRenderEngine(), buffer);
     if (bufferBond.getStatus() != NO_ERROR) {
         ALOGE("got ANWB binding error while taking screenshot");
         return INVALID_OPERATION;