Remove ISA from boot image name.

Partially reverts b9beb2e2efb6a204a69ca660d478b45f851e8f09

Bug: 14882223
Change-Id: Ie85bcf593cb25a58090d4cbbe37392bed6a454fd
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index 7d7024a..ad796f8 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -958,9 +958,7 @@
   bool image = (!image_filename.empty());
   if (!image && boot_image_filename.empty()) {
     boot_image_filename += GetAndroidRoot();
-    boot_image_filename += "/framework/boot-";
-    boot_image_filename += GetInstructionSetString(instruction_set);
-    boot_image_filename += ".art";
+    boot_image_filename += "/framework/boot.art";
   }
   std::string boot_image_option;
   if (!boot_image_filename.empty()) {
diff --git a/runtime/parsed_options.cc b/runtime/parsed_options.cc
index c6e8633..59f63b0 100644
--- a/runtime/parsed_options.cc
+++ b/runtime/parsed_options.cc
@@ -689,9 +689,7 @@
 
   if (compiler_callbacks_ == nullptr && image_.empty()) {
     image_ += GetAndroidRoot();
-    image_ += "/framework/boot-";
-    image_ += GetInstructionSetString(image_isa_);
-    image_ += ".art";
+    image_ += "/framework/boot.art";
   }
   if (heap_growth_limit_ == 0) {
     heap_growth_limit_ = heap_maximum_size_;