Remove unnecessary min_sdk_version from //chrome

Having these causes apks to disable dex merging, making builds a bit
slower.

Bug: None
Change-Id: I33903834529b5c2e1fec43cb81c3d076ca899055
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2367648Reviewed-by: Peter Kotwicz <pkotwicz@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800658}

chrome/android/webapk/libs/runtime_library/javatests/apk_with_webapk_service/BUILD.gn

@@ -11,10 +11,6 @@ android_apk("apk_with_webapk_service") {
   # Used as an additional_apk in test scripts.
   never_incremental = true
 
-  # Multidex requires a custom Application class to initialize it. Simpler to
-  # just disable it.
-  enable_multidex = false
-
   android_manifest = "AndroidManifest.xml"
   apk_name = "ApkWithWebApkService"
   sources = [ "src/org/chromium/webapk/lib/runtime_library/test/TestWebApkServiceImplWrapper.java" ]
@@ -22,5 +18,4 @@ android_apk("apk_with_webapk_service") {
     "//chrome/android/webapk/libs/runtime_library:runtime_library_for_tests_java",
     "//chrome/android/webapk/libs/runtime_library:webapk_service_aidl_java",
   ]
-  min_sdk_version = 16
 }

chrome/android/webapk/shell_apk/javatests/dex_optimizer/BUILD.gn

@@ -19,7 +19,6 @@ android_apk("dex_optimizer_apk") {
   enable_multidex = false
 
   android_manifest = "AndroidManifest.xml"
-  min_sdk_version = 16
   apk_name = "DexOptimizer"
   chromium_code = false
   sources = [ "src/org/chromium/webapk/shell_apk/test/dex_optimizer/DexOptimizerServiceImpl.java" ]

chrome/browser/android/examples/custom_tabs_client/BUILD.gn

@@ -64,7 +64,6 @@ android_apk("custom_tabs_client_example_apk") {
   ]
 
   android_manifest = "src/AndroidManifest.xml"
-  min_sdk_version = 19
   target_sdk_version = 21
   apk_name = "CustomTabsClientExample"